Audit of the California Department of Corrections and Rehabilitation’s Management of Temperature Conditions Within California’s Prisons

Amarik K. Singh, Inspector General Shaun Spillane, Chief Deputy Inspector General of the OFFICE OIG INSPECTOR GENERAL Independent Prison Oversight September 2025 Audit of the California Department of Corrections and Rehabilitation’s Management of Temperature Conditions Within California’s Prisons AUD № 24–02 Electronic copies of reports published by the Office of the Inspector General are available free in portable document format (PDF) on our website. We also offer an online subscription service. For information on how to subscribe, visit www.oig.ca.gov. For questions concerning the contents of this report, please contact Shaun Spillane, Public Information Officer, at 916-288-4212. Connect with us on social media September 11, 2025 Mr. Jeffrey Macomber Secretary California Department of Corrections and Rehabilitation P.O. Box 942883 Sacramento, CA 94283-001 Dear Mr. Macomber: Enclosed is the Office of the Inspector General’s (the OIG) report titled Audit of the California Department of Corrections and Rehabilitation’s Management of Temperature Conditions Within California’s Prisons. California Penal Code section 6126, subdivisions (b) and (c) authorize the OIG to initiate audits of the California Department of Corrections and Rehabilitation’s (the department) policies, practices, and procedures. In this audit, the OIG assessed the department’s effectiveness in managing extreme temperatures that occur in California’s prisons. We reviewed departmental policies and procedures relative to the management of temperatures in prisons including the heat plan implemented by California Correctional Health Care Services and the department. The heat plan, which arose out of the Coleman v. Newsom litigation, requires prison staff to document temperatures in housing units daily to determine whether staff must take protective measures for incarcerated people taking medications that may make them sensitive to the heat, and thus can cause heat-related illness—including death—in some individuals. We completed an in-depth review of the department’s preparedness for extremely hot and cold temperatures at three prisons—High Desert State Prison, California State Prison, Corcoran, and California State Prison, Los Angeles County—located in different parts of the state. We reviewed indoor temperature logs at these three prisons to assess the department’s accuracy in documenting temperatures as required by the heat plan, investigated the methods used for managing extreme heat, and evaluated the three prisons’ capacity to maintain reasonable temperatures in housing units. Our audit found that at the three prisons we reviewed, temperatures could not consistently be maintained within departmental design guidelines of 68 to 89 degrees Fahrenheit inside the housing units. We also found that custody staff at the three prisons we reviewed did not consistently complete heat logs as required by the heat plan. When prison staff are not regularly monitoring temperatures in the housing units, they may not take precautionary measures when there is excessive heat, which jeopardizes the health and safety of the incarcerated population. The heat logs were reviewed to confirm whether the temperatures in housing units were within design guidelines. Because staff did not document temperatures in housing units each day, the number of days temperatures were above or below departmental design Gavin Newsom, Governor 10111 Old Placerville Road, Suite 110 Sacramento, California 95827 Telephone: (916) 288-4212 www.oig.ca.gov Mr. Jeffrey Macomber, Secretary September 11, 2025 Management of Temperature Conditions in Prisons Page 2 guidelines at the prisons we reviewed could have been higher than what we could identify through available records. In June 2024, California’s Occupational Safety and Health Standards Board approved California Code of Regulations, Title 8, section 3396, “Heat Illness Prevention in Indoor Places of Employment.” These regulations are designed to establish safety measures for indoor workplaces to prevent exposing employees to the risk of heat illness. Although these regulations exempted prisons, the department is working with the California Department of Industrial Relations to reach an agreement on indoor heat regulations within which the department can operate. Possibly the most significant contributing factor impacting the prisons’ ability to maintain temperatures in housing units within the departmental guidelines is the prevalence of heating and cooling equipment that has exceeded its useful life: some systems are more than 30 years old. For example, at Corcoran, plant operations staff faced challenges with completing preventive maintenance to keep heating and cooling equipment from failing. Corcoran also found it difficult to procure replacement parts to repair heating and cooling systems, with the prison receiving parts weeks or months after being ordered. Management staff at department headquarters acknowledged several prisons throughout the state have equipment that has exceeded its useful life; equipment failure is common and often requires emergency repairs. The department has long acknowledged the challenges it has with its aging infrastructure, including heating and cooling systems. On a positive note, the department is pursuing a pilot program at four prisons to explore and study different options for cooling and insulating housing units for the incarcerated population. If successful, the department will explore options to upgrade housing units at other prisons. Finally, the department does not take year-round measures to protect other vulnerable incarcerated individuals aside from those the department is required to protect under the heat plan. More than 40 percent of the prison population is over the age of 45, with this portion of the population quickly growing. Many of these individuals are more vulnerable, much like the individuals who take medications that may make them sensitive to the heat. We also point out individuals may suffer more health-related risks during cold weather, and the department should consider offering clothing options such as thicker jackets to incarcerated individuals who may be less tolerant of cold temperature conditions. Following publication, we request that the department provide its status on implementing our recommendations at intervals of 60 days, six months, and one year from the date of the audit. Respectfully submitted, Amarik K. Singh Inspector General Return to Contents OIG Report AUD № 24–02, Management of Temperature Conditions in Prisons | iii Contents Illustrations v Introduction 1 Background 1 The Department Operates Several Different Types of Heating and Cooling Systems in Prisons 3 The Effects of Excessive Heat Temperatures on the Incarcerated Population 5 The Department Must Monitor Temperatures in Prison Housing Buildings 7 Results 11 Chapter 1. Temperatures in Prison Housing Units Frequently Fell Outside Acceptable Temperature Ranges, and Staff’s Failure to Consistently Complete Heat Logs Hindered the OIG’s Ability to Effectively Analyze the Full Extent of These Temperature Variations 11 Prison Housing Units Reach Temperatures Outside the Design Guideline Range 11 Custody Staff Did Not Consistently Maintain Heat Logs at the Prisons We Reviewed as Required by Ongoing Litigation 15 Recommendations 17 Chapter 2. Budget Challenges and Inconsistent Completion of Preventive Maintenance Inhibit the Department’s Ability to Maintain Outdated Heating and Cooling Equipment 18 Prisons Do Not Consistently Perform Preventive Maintenance on Their Heating and Cooling Systems 18 Although Budgetary Constraints Present Challenges for the Department to Maintain its Heating and Cooling Systems, It Is Seeking Budget Increases to Update and Replace its Aging Equipment 20 Recommendations 21 Chapter 3. The Department Does Not Protect a Significant Number of Vulnerable Incarcerated Individuals From Heat or Cold 23 The Department Does Not Have Statewide Policies to Protect Most of the Incarcerated Population From Heat 23 Office of the Inspector General, State of California Return to Contents iv | OIG Report AUD № 24–02, Management of Temperature Conditions in Prisons The Department Could Provide Additional Measures to Protect the Incarcerated Population at Prisons From Cold Weather 24 Recommendations 26 Appendix 27 Scope and Methodology 27 Assessment of Data Reliability 30 The Department’s Response to Our Report 31 Office of the Inspector General, State of California Return to Contents OIG Report AUD № 24–02, Management of Temperature Conditions in Prisons | v Illustrations Figures 1. Cooling Unit Types in California State Prison Housing Units 5 Tables 1. Heat Stages and Requirements 9 2. Housing Units Tested at Three Prisons With Temperatures Exceeding 89°F 12 3. Housing Units Tested at Three Prisons With Temperatures Below 68°F 13 4. Top Five Housing Units at Each of the Three Prisons the OIG Reviewed and the Number of Days of Noncompliance at Each Housing Unit 16 A–1. Audit Objectives and Methodology 28 Photographs 1. Steam Seeping From Cracked Pipes at California State Prison, Corcoran 6 2. Housing Unit at California State Prison, Corcoran 7 3. An Evaporative Cooling System at California State Prison, Corcoran 19 Office of the Inspector General, State of California Return to Contents vi | OIG Report AUD № 24–02, Management of Temperature Conditions in Prisons (This page left blank for reproduction purposes.) Office of the Inspector General, State of California Return to Contents OIG Report AUD № 24–02, Management of Temperature Conditions in Prisons | 1 Introduction California Penal Code section 6126(b) authorizes the Office of the Inspector General (the OIG) to conduct audits of the California Department of Corrections and Rehabilitation’s (the department) policies, practices, and procedures. We initiated this audit to review and evaluate the control measures the department has in place to detect and respond to excessive interior temperatures in its prisons’ housing units. During this audit, we reviewed the department’s specific policies and procedures relative to the department’s management and maintenance of temperature conditions in California prisons. We focused on how departmental policies and procedures are designed to ensure the health and safety of the incarcerated population during extreme temperature conditions. We selected three prisons for our audit: California State Prison, Corcoran (Corcoran), California State Prison, Los Angeles County (Lancaster), and High Desert State Prison (High Desert). During our audit period, from August 1, 2022, through July 31, 2024, we requested and reviewed documents from these prisons that support the department’s actions relative to both the management and the maintenance of temperatures in prisons. We also interviewed key personnel, conducted on-site observations, reviewed selected documentation, and tested key controls relevant to the audit objectives. Background In an increasingly changing climate, California’s prison staff are challenged to maintain indoor temperatures that protect the incarcerated population from the extremes of heat and cold. Many prison buildings are old and were built without consideration for the comfort level of the incarcerated people housed in them. California has 31 prisons throughout the State that vary in age and location.1 San Quentin Rehabilitation Center is the State’s oldest prison, built in 1852. The State’s newest prison is California Health Care Facility in Stockton, California, built in 2013. Prisons are located throughout the State in a variety of different geographic locations with widely diverse climates, from Pelican Bay State Prison in Crescent City just south of the Oregon border, to the Richard J. Donovan Correctional Facility in San Diego, California. A significant number of prisons are located in areas with climates that experience extreme heat in the summer and extreme cold in the winter. 1. There are currently 31 active prisons. Over the course of our audit period, two institutions closed; California Correctional Center closed in June of 2023, and Chuckawalla Valley State Prison closed in October of 2024. However, these closures did not impact our audit, and we refer to 31 institutions throughout our report for ease of reference. Office of the Inspector General, State of California Return to Contents 2 | OIG Report AUD № 24–02, Management of Temperature Conditions in Prisons In 1980, the department established statewide design guidelines that set indoor temperature standards for its prisons. These guidelines required certain areas to maintain indoor temperatures at a minimum of 68 degrees Fahrenheit and a maximum of 89 degrees Fahrenheit2 to provide a suitable indoor environment for thermal comfort. However, the department’s existing systems for cooling and warming the indoor temperatures of prisons are not always capable of meeting this standard. Not only are many prisons located in regions where temperatures regularly exceed 100°F in summer months and fall below 40°F in winter months, the dated infrastructure of the State’s prisons creates significant challenges for plant and facility operations staff to maintain equipment that can adequately keep temperatures within these guidelines to ensure safe conditions for both the incarcerated population and prison staff. The last eight years have been the warmest on record, which has exacerbated the problem. Several prisons are outfitted with heating and cooling systems that are 30 or more years old, which can present significant challenges for plant operations staff to repair and maintain in working condition. In 2020, the Legislative Analyst’s Office (LAO) published a report examining the state of the department’s infrastructure; it highlighted a study that found most of the department’s buildings and systems had not been updated since their original construction dates, they generally exceeded their expected useful life, and were often not consistent with building code requirements for elements such as fire sprinklers and kitchen ventilation. The study recommended more than 150 specific infrastructure improvement projects that would cost over $11 billion to implement for the State’s 12 oldest prisons. The LAO report estimated the remaining 22 prisons would likely require an additional $8 billion in maintenance and repairs.3 Since the release of the LAO’s report, and in line with its recommendations, the department has closed three prisons after considering the buildings’ age and physical condition. In its December 31, 2021, Sustainability Roadmap,4 the department acknowledged the importance of understanding current and future impacts of climate change, and the necessity of proactively planning for those impacts. This is particularly important in California, where, as the department’s Sustainability Roadmap points out, temperatures have increased 1.8°F over the past century, and the number of extreme heat events are expected to increase across the State. In part, to prepare for these changes, the department requested funding for a pilot program to 2. In this report, hereafter, temperatures will be expressed in Fahrenheit and abbreviated using standard scale references, e.g., 90°F. 3. The 2020-21 Budget: Effectively Managing State Prison Infrastructure, February 28, 2020 (Sacramento, CA: Legislative Analyst’s Office, 2020). 4. Sustainability Roadmap, December 31, 2021, California Department of Corrections and Rehabilitation: Progress Report and Plan for Meeting the Governor’s Sustainability Goals for California State Agencies (California Department of Corrections and Rehabilitation, 2021). Office of the Inspector General, State of California Return to Contents OIG Report AUD № 24–02, Management of Temperature Conditions in Prisons | 3 begin the long process of replacing equipment at four prisons, which we will discuss in further detail in this report.5 Half of the department’s prisons are in areas with moderate to high summer temperatures, and the department has had to adapt to operating prisons in areas that endure periods of high daily temperatures. For example, in 2024, 20 of the department’s prisons experienced 30 or more days of temperatures exceeding 100°F. Ironwood State Prison, located in Blythe, California, recorded the highest number, with 136 days of temperatures that exceeded 100°F, followed closely by Calipatria State Prison, located in Calipatria, California, and California State Prison, Centinela, located in Imperial, California, each recording 135 days with temperatures that exceeded 100°F. In contrast, in 2024, 22 prisons experienced more than 30 days of temperatures below 40°F. High Desert State Prison located in Susanville, California, had 195 days in 2024 with temperatures below 40°F, with a minimum temperature of 3°F in January 2024. California Correctional Institution, located in Tehachapi, California, had 155 days below 40°F, and Sierra Conservation Center, located in Jamestown, California, had 115 days below 40°F. In June 2024, California’s Department of Industrial Relations’ Occupational Safety and Health Standards Board approved regulations to prevent heat illness in indoor workplaces. Although prisons are exempt from these regulations, the department is working with the Department of Industrial Relations to establish suitable guidelines for correctional facilities. The Department Operates Several Different Types of Heating and Cooling Systems in Prisons Due to the different ages of prisons and their associated infrastructures, various types of heating and cooling systems are used to manage temperatures in prison facilities. To keep buildings cool, some prisons use mechanical refrigeration cooling, what most people understand as air conditioning, and some use only evaporative cooling, known colloquially as swamp cooling. Some prisons have no dedicated cooling system at all and use ventilation only. To keep buildings warm, some prisons use a combination of different heating systems. To reiterate: design guidelines for prisons are set to maintain indoor temperatures at a range between 68°F and 89°F, which means some of these methods result in substandard outcomes. The most basic design for cooling housing units in a prison is ventilation without any other type of mechanical refrigeration or evaporative cooling. Ventilation without cooling pulls in fresh air from the outside but has no means to actively cool the existing inside air. Because a 5. California Budget Change Proposal 5225-066-BCP-2025-GB (Proposed to the Department of Finance on January 10, 2025). Office of the Inspector General, State of California Return to Contents 4 | OIG Report AUD № 24–02, Management of Temperature Conditions in Prisons ventilation system does not actively cool the inside air, it does not typically provide temperature relief, especially when the air outside exceeds the temperature of the air inside. The department operates seven prisons that have at least some housing units using this style of system. The department uses evaporative cooling in 21 of its 31 prisons. Evaporative cooling systems pull in air from the outside and pass it over water-saturated pads. As the water evaporates, the effect lowers the air temperature somewhat. Currently, evaporative cooling is the most common way to cool California prisons. This type of system can work effectively in dry climates, but it is not especially effective in humid climates due to the presence of excessive moisture in the atmosphere. Evaporative cooling requires a large amount of water. Mechanicals for the evaporative system are often situated on rooftops, but they can also be found in secured equipment rooms above the housing units. The water from the source runs through pipes that can leak, which can cause structural damage, such as on the roof or in other structural elements. The water in the pipes can also cause rust, which weakens the overall integrity of the system. Moreover, evaporative cooling is ineffective when the outside temperature exceeds 100°F. Evaporative cooling systems can only lower the temperature of an area by 10°F to 15°F, depending on the size of the indoor space. This limitation means that many prisons located in the central and southern parts of California—where temperatures can exceed 100°F for several days in a row—simply cannot reduce the temperature below the maximum temperature limit specified by the design criteria. As a result, prisons such as Corcoran, where temperatures can exceed 100°F for several days in a row, have recorded indoor temperatures as high as 95°F despite operating an evaporative cooling system. Mechanical refrigeration systems are generally considered the most effective systems for cooling indoor temperatures in housing units. However, this is not the most common cooling system available in the State’s prisons. Mechanical refrigeration cooling systems are also less effective if a building has poor insulation, as prisons do. Ironwood State Prison, located in Blythe, California, where summer temperatures can exceed 100°F for several days at a time, is one of the few prisons that use mechanical refrigeration cooling. However, departmental staff have acknowledged that even with mechanical refrigeration cooling systems in place, the prisons continue to struggle to keep temperatures in buildings within the design guidelines. Figure 1 on the next page shows the distribution of these three types of cooling systems used in California’s State prisons. While health concerns associated with cold temperatures, such as hypothermia, are usually associated with colder regions of the world where severe winters are prevalent, they may also be experienced in milder climates including regions in California. For these reasons, as Office of the Inspector General, State of California Return to Contents OIG Report AUD № 24–02, Management of Temperature Conditions in Prisons | 5 Figure 1. Cooling Unit Types in California State Prison Housing Units Evaporative Mechanical Ventilation Cooling Refrigeration Without Cooling Cooling Source: The department’s data on cooling types by institution. temperatures drop in the winter, it is important for prisons to maintain temperatures at comfortable levels. To accomplish this, the department uses a variety of heating systems. The most common method of heating the housing units is through direct gas-fired furnaces in air handling units (AHUs). The second most common method of heating is through hot water/hydronic heating coils in AHUs, in which hot water is generated by gas-fired water heaters, or from steam, and is then passed to hot water heat exchangers and distributed to AHUs. However, many of these systems are old, and the pipes that deliver the steam can break over time, causing leaks that make the system less efficient, as pictured in Photo 1 on the next page. The Effects of Excessive Heat Temperatures on the Incarcerated Population The manner in which the human body reacts to extreme temperatures depends on the body’s ability to regulate temperature. The body regulates its temperature using biological mechanisms, such as sweating or shivering, to help maintain a stable internal core temperature of about 98°F. Each individual’s ability to thermoregulate is unique, however, and can depend on age, medical conditions, and medications being taken. One study found that from 2016 to 2020, California had the fifth highest number of incarcerated individuals exposed to potentially dangerous Office of the Inspector General, State of California stinU gnilooC fo rebmuN 900 800 830 N = 1,556 700 Total Cooling Units 600 500 400 447 300 200 279 100 0 Type of Cooling Units Return to Contents 6 | OIG Report AUD № 24–02, Management of Temperature Conditions in Prisons Photo 1. Steam seeping from cracked pipes at California State Prison, Corcoran. Source: OIG audit staff. heat days, following Texas, Florida, Arizona, and Louisiana.6 Most of the department’s institutions were built at a time when the comfort level of the incarcerated population was not a consideration or a priority.7 These prisons were generally built with materials that retain heat and do not provide insulation from hot or cold temperatures, such as concrete. As depicted in Photo 2 on the next page, most living areas for incarcerated individuals consist of cells with small, closed windows. Extreme heat has been linked to an increased likelihood of death and violence among the incarcerated population. Studies have linked higher temperatures to an increased prevalence of aggression, self-harm, and suicide attempts. For example, a study found that daily suicide incidents increased by 29 percent when the temperature reached 80°F to 89°F, and by 36 percent when temperatures reached 90°F to 103°F, compared with temperatures between 60°F to 69°F.8 Individuals who take mental health medications are at increased risk of developing adverse effects including life-threatening conditions when exposed to excessive heat. Moreover, studies have found that the characteristics of prisons, such as 6. Cascade Tuholske, Victoria D. Lynch, Raenita Spriggs, et al., “Hazardous Heat Exposure Among Incarcerated People in the United States,” Nature Sustainability 7 (2024), 394–98. 7. California Budget Change Proposal 5225-066-BCP-2025-GB (January 10, 2025). 8. David H. Cloud, Brie Williams, Regine Haardörfer, et al., “Extreme Heat and Suicide Watch Incidents Among Incarcerated Men,” JAMA Network Open, Vol. 6, No. 8 (2023). Office of the Inspector General, State of California Return to Contents OIG Report AUD № 24–02, Management of Temperature Conditions in Prisons | 7 Photo 2. Housing unit at California State Prison, Corcoran. Source: OIG audit staff. overcrowding, isolation, and severely restricted movement, can further exacerbate an incarcerated person’s vulnerability to heat exposure. 9 The Department Must Monitor Temperatures in Prison Housing Buildings In addition to the concerns outlined above, the department is charged with maintaining adequate temperature records in accordance with the heat plan requirements developed in the Coleman v. Newsom10 litigation—a case in which the department was found to have violated the Eighth Amendment by demonstrating deliberate indifference to the mental health needs of incarcerated individuals. The court recommended the development of remedial plans to address the constitutional failures, including devising a heat management plan (heat plan) for incarcerated people who must take medications that can result in heat sensitivity. As a result, the parties agreed to a stipulated order that became the foundational framework of the heat plan. More than three decades after the case was filed, the court continues to monitor the heat plan, in part because of the challenges with full and adequate implementation. 9. Ufuoma Ovienmhada, Mia Hines-Shanks, Michael Krisch, et al., “Spatiotemporal Facility-Level Patterns of Summer Heat Exposure, Vulnerability, and Risk in United States Prison Landscapes,” Geohealth (2024). 10. Coleman v. Newsom 131 F.4th 948 (2025). Office of the Inspector General, State of California Return to Contents 8 | OIG Report AUD № 24–02, Management of Temperature Conditions in Prisons The heat plan sets forth requirements that prisons must develop, implement, and maintain to prevent serious threats to the life and health of incarcerated individuals. This is especially important for those taking medications that can impair the body’s ability to regulate temperature. During periods of excessive heat, these individuals are at higher risk of developing serious, life-threatening conditions. According to the department, in general, “the heat plan is in effect from May 1st through October 31st of each year.” One prison we reviewed, Lancaster, has a local policy in place that states the heat plan is in effect year-round “due to the local variant weather and temperatures.”11 The heat plan consists of three different stages, as specified in Table 1 on the next page. Annually, the department is required to distribute to prisons a list of heat-alert medications people take that could subject them to a heat risk. For the period that the heat plans are in effect at prisons, prison staff must receive a daily list of all incarcerated people who are taking medications that may cause life-threatening conditions due to excessive heat. Prison staff must also measure and record the temperature in all living areas housing incarcerated people who may be taking medications that make them sensitive to extreme heat, buildings without an air-cooling system, or buildings with a cooling system if the temperature in the building could exceed 90°F. This includes work locations, such as kitchens. 11. The department provided the OIG with copies of the local operating procedures that lay out these heat plans. This quotation is from the heat plan procedures document for Lancaster, developed 2016, and revised May 2024. Office of the Inspector General, State of California Return to Contents OIG Report AUD № 24–02, Management of Temperature Conditions in Prisons | 9 Table 1. Heat Stages and Requirements Heat Stage Requirement • Warden or designee announces and activates Stage I Heat Plan institution wide. Stage I • At risk incarcerated people called for “Return to Housing.” Occurs when the temperature • Incarcerated people are given 30 minutes to complete certain tasks outside rises to 90°F or more. before returning to housing. Return to housing • Continue to monitor outside temperature. • Stage I Heat Alert deactivated when outside temperatures fall below 90°F for one hour. • Warden or designee activates Stage II Heat Plan in the Stage II affected area. • Staff initiate cooling and hydration measures. Occurs when the temperature inside rises to 90°F or more. • Staff increase observation of heat-risk incarcerated people for signs of heat related illness. Report any symptoms to health care staff. Increased observation, cooling • Continue to monitor inside temperature. and hydration measures • Stage II Heat Alert deactivated when the inside temperature falls below 90°F for one hour. • Warden or designee activates Stage III Heat Plan in the affected area. Stage III • Nursing or other medically trained personnel perform medical rounds on heat risk incarcerated people at least once every two Occurs when the temperature hours and record their condition. inside any area occupied by a heat-risk incarcerated person • Any incarcerated person showing signs or symptoms of heat related rises to 95°F or more. illness is provided cooling measures or sent to the triage and treatment area. Medically trained • Continue to monitor the inside temperature. personnel rounds • Stage III Heat Alert deactivated when the inside temperature falls below 95°F for one hour. Source: The department’s Heat Plan Basics handout for heat plan requirements. The OIG receives numerous complaints from the incarcerated population regarding extreme temperature conditions in their prison housing units. Some complaints arrive during the summer months and reflect concerns about excessive temperatures in housing units and a lack of effort from the prisons to cool the incarcerated population during periods of excessive heat. Some complaints claim temperatures in cells can exceed 90°F. Other complaints note chronic issues with cooling and heating equipment that is regularly in disrepair for long periods. To mitigate the excessive heat situation, when prisons experience excessive heat, the incarcerated population is typically allowed greater access to showers and ice as outlined in the heat plan. Office of the Inspector General, State of California Return to Contents 10 | OIG Report AUD № 24–02, Management of Temperature Conditions in Prisons (This page left blank for reproduction purposes.) Office of the Inspector General, State of California Return to Contents OIG Report AUD № 24–02, Management of Temperature Conditions in Prisons | 11 Results Chapter 1. Temperatures in Prison Housing Units Frequently Fell Outside Acceptable Temperature Ranges, and Staff’s Failure to Consistently Complete Heat Logs Hindered the OIG’s Ability to Effectively Analyze the Full Extent of These Temperature Variations Maintaining acceptable temperatures in the State’s prison housing units is challenging for several cascading reasons. Regional temperatures in areas where some prisons are located can exceed 100°F or fall below 40°F for many consecutive days, lack of appropriate and updated heating and cooling systems allow temperatures in prison housing units to reach unacceptable levels, and the aging infrastructure of prison buildings can prevent even the best available heating and cooling system from operating efficiently. In addition, staff at the three prisons we reviewed did not consistently maintain heat logs, which can cause the prisons to be out of compliance with the heat plan, hinder a full understanding of the extent of the problem, and could lead to unknowingly putting incarcerated people or staff at risk of suffering from extreme temperatures. Prison Housing Units Reach Temperatures Outside the Design Guideline Range Both excessively hot temperatures and excessively cold temperatures can negatively affect the incarcerated population and departmental staff who work inside prison housing units. We reviewed heat logs from August 2022 through October 2023 at three prisons—Corcoran, High Desert, and Lancaster. We found that these prisons did not consistently maintain temperatures inside housing units in accordance with design guidelines. Not only did we find that these prisons recorded temperatures in housing units that exceeded the 89°F guideline, the temperature also fell below the 68°F design guideline. Excessive heat is typically the most concerning factor because significant heat-related illnesses can occur among sensitive populations, especially those incarcerated people taking medications that can cause heat sensitivity. Of the three prisons we reviewed over a 15-month period, Corcoran had the greatest number of housing units with temperatures that exceeded the design guidelines of 89°F. At Corcoran, 23 of the prison’s 33 housing units (70 percent) had one or more days in which indoor temperatures were above 89°F. In particular, Office of the Inspector General, State of California Return to Contents 12 | OIG Report AUD № 24–02, Management of Temperature Conditions in Prisons at one housing unit, custody staff recorded 23 days with temperatures that exceeded the maximum design guideline of 89°F. Lancaster had 10 of 29 housing units with one or more days above 89°F. High Desert had the fewest number of housing units with temperatures that exceeded 89°F; three of 27 housing units (11 percent) recorded an indoor temperature above 89°F. High Desert had the fewest number of days recorded with temperatures above the 89°F design guideline. High Desert is located in a higher elevation, which likely results in milder summer temperatures than other parts of the state. However, several prisons, including Corcoran, are in the Central Valley of California, and likely experienced similar days of excessive heat. Table 2 below shows the number of housing units at the three prisons we tested that exceeded temperatures of 89°F. Table 2. Housing Units Tested at Three Prisons With Temperatures Exceeding 89°F Number of Housing Units Most Days Number That Had One Over 89°F of Housing or More Days in a Single Prison Units Tested Over 89°F Housing Unit High Desert 27 3 1 Lancaster 29 10 2 Corcoran 33 23 23 Source: Department heat logs from California State Prison, Corcoran (Corcoran); California State Prison, Los Angeles County (Lancaster); and High Desert State Prison, (High Desert); from August 1, 2022, through October 31, 2023. This table reflects data from the months of May 1, 2023, through October 31, 2023. At the three prisons we reviewed, temperatures inside several housing units fell below the minimum allowable temperature of 68°F. During our 15-month review period, High Desert maintained a heat log for some housing units year-round. Although recording temperatures year-round was not required by the heat plan, the fact that they were recorded gave our team an opportunity to review indoor housing temperature logs for both winter and summer months. During the 15-month review period of August 1, 2022, through October 31, 2023, High Desert had one housing unit with recorded temperatures below 68°F for 127 days. Some of High Desert’s housing units recorded temperatures below 55°F during winter months. Temperatures lower than 55°F in a housing unit can be challenging for those individuals vulnerable to cold temperatures due to medical conditions and for those whose movements are restricted. Office of the Inspector General, State of California Return to Contents OIG Report AUD № 24–02, Management of Temperature Conditions in Prisons | 13 When the OIG tested only the summer months (May 1 through October 31) of the review period, High Desert’s heat logs revealed that 21 of its 27 housing units (78 percent) still recorded temperatures in housing units below 68°F. In one housing unit, the temperature fell below 68°F on 112 days during the summer months. As shown in Table 3 below, Lancaster’s restricted housing unit (RHU) logged the greatest number of days below the 68°F design guideline, dropping as low as 60°F, with one housing unit recording 221 days below 68°F when looking at the summer months. When winter months were included in the review period, Lancaster had a different housing unit that recorded 301 days below 68°F.12 Although we are not aware of any complaints from the incarcerated population regarding temperatures in the RHUs during our test period, we nevertheless wanted to highlight the number of days in which the temperature fell below design guidelines. Table 3. Housing Units Tested at Three Prisons With Temperatures Below 68°F Number of Housing Units Most Days Number That Had One Below 68°F of Housing or More Days in a Single Prison Units Tested Below 68°F Housing Unit High Desert 27 21 112 Lancaster 29 26 221 Corcoran 33 29 98 Source: Department heat logs from California State Prison, Corcoran (Corcoran); California State Prison, Los Angeles County (Lancaster); and High Desert State Prison, (High Desert); from August 1, 2022, through October 31, 2023. This table reflects data from the months of May 1, 2023, through October 31, 2023. As Tables 2 and 3 show, at the three prisons we reviewed, several housing units did not maintain temperatures within design guidelines. Prisons are not only living places for the incarcerated population, they are also places of work for both custody and medical staff. While the California Occupational Safety and Health Standards Board (Cal/OSHA) approved regulations establishing required safety measures for most indoor workplaces to prevent the risk of heat illness to workers, prisons were excluded from those regulations and protections. California is not the only state struggling with excessive temperatures inside its prisons. In Texas, regulations require that the temperature inside jails be maintained at reasonable levels between 65°F and 85°F. 12. Lancaster’s RHU is cooled with mechanical refrigeration cooling, and as such, is generally not required to have its temperatures measured and recorded in accordance with the heat plan. Nevertheless, Lancaster did record the temperatures in its RHU living areas, which allowed us to verify compliance with the design guidelines as depicted in Table 3. Office of the Inspector General, State of California Return to Contents 14 | OIG Report AUD № 24–02, Management of Temperature Conditions in Prisons These temperatures are lower than the department’s current design guidelines and would be particularly challenging for prisons to meet. Specifically, at Corcoran, 33 housing units had one or more days over 85°F and 24 housing units had one or more days below 65°F. While maintaining temperature levels between 65°F and 85°F is required by Texas regulations for its jails, it is not a requirement for its prisons, which face scrutiny for their high temperatures. For example, the Texas Department of Criminal Justice was sued by an incarcerated person housed in a prison cell without air conditioning who suffered from stroke symptoms that were exacerbated by the heat. The court found that logs showed indoor temperatures above 85°F occurred nearly every day from May 1, 2023, to September 30, 2023, and concluded that the excessive heat was likely serving as a form of unconstitutional punishment. Given Cal/OSHA’s established standard, and considering the ongoing litigation in states like Texas, which may result in stricter temperature regulations in prisons, it is reasonable to presume that the department will need to implement solutions to ensure indoor temperatures fall below the current design standard of 89°F. To gain a sense of the prevailing atmosphere in the California prison setting, we interviewed 20 incarcerated people at High Desert and Corcoran. Several mentioned the excessive temperatures they had experienced in prison buildings and in their cells. One incarcerated person at Corcoran stated the following: It is too hot in the summer, and I had a couple anxiety attacks because there was not enough air flow in the cell in the hot months during lockdown. Another incarcerated person we interviewed at Corcoran found that his cell was much hotter than the dayroom: It is too hot in the cell. I couldn’t breathe at times in my cell, so I try not to be in there as I’ve gone “man down” in the summer a couple times. The day room is cooler than the cells. In our interviews with incarcerated people, they stated that the temperature in their cells is less comfortable than the temperature in the dayrooms. However, these claims cannot be confirmed because temperature readings are not taken in cells. Departmental staff also told auditors that temperature readings were sometimes taken in locations that would not show the most accurate reading, such as locations near doorways. At Lancaster, larger housing units, such as RHUs with separate pods—a group of connected cells—should have the temperature recorded at a centralized location for each individual pod, and not in the middle of the central pod. The plant manager at Lancaster mentioned temperatures could differ depending on the location of the pods, and recording temperatures at the center pod of each housing unit would reflect Office of the Inspector General, State of California Return to Contents OIG Report AUD № 24–02, Management of Temperature Conditions in Prisons | 15 an inaccurate temperature reading. Lancaster is currently recording temperatures in the middle of the center pod but recording them from the center of each individual pod instead would reflect more accurate temperatures. If the department does not address extreme temperature conditions in its prisons, it not only risks being out of compliance with its heat plan, but also risks exposing incarcerated people and staff to potentially life-threatening heat-related conditions. Custody Staff Did Not Consistently Maintain Heat Logs at the Prisons We Reviewed as Required by Ongoing Litigation As noted above, in general, the department’s heat plan requires that staff monitor the temperature in several housing units from May 1 through October 31 each year. Each day during this period, custody staff are required to take temperature readings in the housing units and document those temperature readings in a heat log.13 When temperature readings are not performed, not only is the prison out of compliance with the heat plan, but the prison may not realize the need to take measures to protect vulnerable individuals who may be at elevated risk of heat-related illness. Failure to follow proper precautions required by the heat plan could cause incarcerated people to suffer serious heat-related illnesses. During our review period, we identified multiple days in which custody staff failed to perform and document temperature readings in several housing units. At Lancaster, staff failed to record the temperature in one housing unit on 95 days from January 1 through December 31. At High Desert, staff did not record the temperature in one housing unit on 13 days during the required time frame from May 1 through October 31. Corcoran had the highest compliance, with only seven or fewer days when custody staff did not document housing unit temperatures in the heat log. Table 4 on the next page shows the top five housing units at each prison we tested that were out of compliance with temperature recording requirements, and the number of days of noncompliance. Because prisons often failed to document temperature readings in the heat logs, it is possible that the actual number of days each prison was out of compliance with the departmental design guidelines was even greater than the figures we noted in Tables 2 and 3. Lancaster is unique in that it established local operating procedures to document temperatures in its housing units on a year-round basis. However, we found that Lancaster did not always follow its local procedure to record temperatures year-round. In fact, we found that custody staff did not keep records for days or weeks at a time for 21 housing units at Lancaster. When we brought this lapse to the prison’s 13. Staff are not required to document temperature readings in housing units that use mechanical refrigeration cooling systems. Office of the Inspector General, State of California Return to Contents 16 | OIG Report AUD № 24–02, Management of Temperature Conditions in Prisons attention, staff initially told our auditors that they were not required to maintain heat logs year-round. This representation, however, was in direct contradiction with Lancaster’s local operating procedures. Although we acknowledge that Lancaster’s local procedures to keep heat logs year-round exceed the requirements under the department’s statewide heat plan, the prison should nevertheless follow its own local operating procedures or reevaluate these procedures to determine their necessity. Table 4. Top Five Housing Units at Each of the Three Prisons the OIG Reviewed and the Number of Days of Noncompliance at Each Housing Unit Number of Days With Missing Log Entries Number of Days Percentage of Corcoran * (May 1– October 31 Policy) Housing Units Were Active Noncompliance ‡ Building 2 7 232 3% Building 3 4 92 4% Building 4 3 276 1% Building 5 3 276 1% Building 6 3 276 1% Number of Days With Missing Log Entries Number of Days Percentage of High Desert* (May 1– October 31 Policy) Housing Units Were Active Noncompliance ‡ Building 36 13 190 7% Building 34 12 184 7% Building 37 10 184 5% Building 38 9 190 5% Building 43 9 276 3% Number of Days With Missing Log Entries Number of Days Percentage of Lancaster * † (January 1– December 31 Policy) Housing Units Were Active Noncompliance ‡ Building 60 95 457 21% Building 62 44 457 10% Building 63 36 457 8% Building 64 36 457 8% Building 66 35 457 8% * Building names have been anonymized. † For Lancaster, the temperature logs are required year-round. ‡ Percentage of noncompliance does not include housing units that were closed. Source: Heat log data received from California State Prison, Corcoran; High Desert State Prison; and California State Prison, Los Angeles County (Lancaster) for the period of August 2022 through October 2023. Office of the Inspector General, State of California Return to Contents OIG Report AUD № 24–02, Management of Temperature Conditions in Prisons | 17 The department is aware of the need to maintain and record temperatures in heat logs to maintain compliance with its heat plan and local operating procedures. Clearly, manual logs require resources to keep current, and as we identified above, this manual process is prone to errors and missed temperature readings. Realizing these concerns, the department is installing and testing the functionality of reporting and recording temperatures by using wireless temperature-recording devices at two prisons. If successful, the department plans to consider options for expanding the wireless system. Such an electronic system would likely reduce errors, ensure consistency, and free up staff who currently maintain the heat logs. Recommendations • The department should establish consistent guidelines to monitor and track temperatures in living areas, including those living areas cooled by mechanical refrigeration, on a year-round basis for all incarcerated people. • The department should ensure temperature readings are taken in or at consistent locations in housing units, including separate pods, to ensure the temperature log itself is accurate and consistent. • The department should also consider taking temperature readings in cells to determine whether the temperatures in cells, where incarcerated people spend a significant amount of their time, are more extreme than the temperatures in other living areas. • The department should ensure that all staff are aware of the process used to record temperatures in the heat log and establish a quality control process at prisons to ensure heat logs are accurately completed. Office of the Inspector General, State of California Return to Contents 18 | OIG Report AUD № 24–02, Management of Temperature Conditions in Prisons Chapter 2. Budget Challenges and Inconsistent Completion of Preventive Maintenance Inhibit the Department’s Ability to Maintain Outdated Heating and Cooling Equipment Ensuring the department’s heating and cooling systems function effectively and efficiently throughout the 31 California prisons is accomplished by many individuals carrying out an ongoing series of complex responsibilities. At the start, preventive maintenance tasks are automated by a standardized application in the department’s computer system that generates tasks scheduled to occur at different times depending on factors such as when equipment was entered into the system, the equipment’s manufacturer’s specifications, and industry standards. As a result, preventive maintenance schedules vary for each piece of equipment. While the system tracks preventive maintenance work orders, it does not effectively prioritize or triage necessary maintenance and repairs. This is a problem because plant operations staff at prisons are not always able to consistently complete regular preventive maintenance or repairs, resulting in delays. The department’s headquarters does not oversee each individual piece of equipment’s preventive maintenance schedule or monitor work order completion; these tasks are the responsibility of each prison. Repair and replacement of outdated infrastructure can cost several millions, if not billions, of dollars, which poses a significant challenge for the department considering available financial resources. Prioritizing preventive maintenance could extend the life of the heating and cooling systems in place until pilot programs and studies can identify the best and most cost-effective mitigation of the problem. Prisons Do Not Consistently Perform Preventive Maintenance on Their Heating and Cooling Systems Timely preventive maintenance and repairs can extend the useful life of equipment used for heating and cooling. Plant operations staff at prisons play a key role in ensuring preventive maintenance and repairs are completed.14 However, after reviewing the data received from two prisons regarding buildings that had undergone preventive maintenance, we found consistency of the preventive maintenance differed substantially. The OIG reviewed maintenance data from High Desert and Corcoran for two different periods—High Desert between March 15, 2023, and October 31, 2024, and Corcoran between July 5, 2023, and October 30, 2024. The difference in review periods was a result of the prisons having implemented a new computerized maintenance 14. State of California, Department of Corrections and Rehabilitation, Statewide Housing Study Engineering Analysis Report (July 19, 2024) 12, 13. Office of the Inspector General, State of California Return to Contents OIG Report AUD № 24–02, Management of Temperature Conditions in Prisons | 19 management system (CMMS) at different times. Plant operations staff at Corcoran explained that the CMMS is a statewide application that tracks work orders for service and maintenance. Plant operations staff were still learning how to input completed work orders into the new system, which may explain why some maintenance work was still outstanding during our audit. Specifically, we found that at High Desert, plant operations staff completed at least one maintenance task at 103 of 104 buildings (99 percent). However, at Corcoran, of the 111 buildings sampled that required preventive maintenance during our review period, 90 buildings (81 percent) had at least one preventive maintenance task completed. Both prisons struggled to close work orders for several preventive maintenance tasks. Although during our audit period High Desert was able to perform preventive maintenance at nearly all buildings, it still had 1,135 of 3,741 work orders and preventive maintenance tasks (30 percent) pending completion or needing the work order closed out in the department’s computer system (discussed in additional detail below). Corcoran faced similar challenges, with 1,682 of 5,499 (31 percent) of work orders and preventive maintenance tasks not completed or closed out. Corcoran had 195 work orders that had been pending completion or were in need of closing out for more than six months. Prioritizing and ensuring preventive measures, such as maintenance tasks, are completed is especially important when existing equipment has been in use for decades. The department’s housing unit cooling study mentions that evaporative cooling AHUs, such as the one at Corcoran, pictured at right in Photo 3, have a median life expectancy of 20 to 25 years. Some existing equipment in use is more than 30 years old. As a result, the aging equipment is prone to frequent breakdowns requiring emergency maintenance, which can interrupt and prevent plant operations staff at prisons from completing ongoing Photo 3. An evaporative cooling system at California State Prison, Corcoran. Source: OIG audit staff. preventive maintenance. Office of the Inspector General, State of California Return to Contents 20 | OIG Report AUD № 24–02, Management of Temperature Conditions in Prisons As noted, preventive maintenance is scheduled in accordance with manufacturer recommendations to increase the useful life of equipment and reduce the need for emergency repairs. While preventive maintenance work can be scheduled into the CMMS as a task, the system does not identify when these tasks become overdue. For a prison to identify that scheduled preventive maintenance has not been completed, staff must generate a report and complete a reconciliation report, so overdue tasks can be reprioritized and completed within a reasonable time frame. The department’s headquarters has not provided a policy or a procedure for plant operations staff to generate such reports; this may be one reason preventive maintenance goes uncompleted for extended periods. Although departmental headquarters staff can review activity in the CMMS, the department delegates management of the workload to each prison’s plant operations staff, which includes ensuring preventive maintenance is completed as scheduled. Because headquarters staff do not follow up with each prison, they are not aware when or if preventive maintenance tasks are completed. If the department required plant operations staff to regularly generate a report that identified overdue preventive maintenance tasks, these tasks could be reassigned, completed, and closed out in the CMMS. Ensuring these preventive maintenance tasks are completed could improve the useful life of existing equipment at Corcoran, and at other prisons. As noted at the beginning of this chapter, the complexity of the maintenance process requires that repair requests follow a particular protocol and order of operations. According to some complaints of excessive temperatures raised by the incarcerated population that we reviewed, a work order must be initiated before the prison’s plant operations staff can complete a repair, which would indicate that the process is likely failing at some point. Despite the ongoing efforts of plant operations staff to repair and maintain the department’s equipment, the aging systems are deteriorating and increasingly prone to failure. This results in each prison’s inability to reliably regulate temperatures in housing units, making living conditions inside at times unbearable and potentially unsafe. Although Budgetary Constraints Present Challenges for the Department to Maintain its Heating and Cooling Systems, It Is Seeking Budget Increases to Update and Replace its Aging Equipment Plant operations staff face two significant challenges that keep them from completing repair work timely on heating and cooling systems: budget constraints for purchasing parts and the time it can take to receive ordered replacement parts. Because of budget constraints, prisons must make the most of their available resources by repairing their existing systems instead of replacing them. Prisons may receive Office of the Inspector General, State of California Return to Contents OIG Report AUD № 24–02, Management of Temperature Conditions in Prisons | 21 some replacement parts within a few days, but other parts can take weeks or months to arrive, which can delay repairs. This clearly affects the department’s mission of providing a safe and humane environment for the incarcerated population and staff. Staff at the prisons we visited also shared their experience with repair work for heating and cooling systems, and the conditions under which they have worked. One correctional officer at Corcoran mentioned to the auditors that when the air conditioning stops working, it can take three to four months for plant operations staff to fix the system, making working conditions very uncomfortable. We also interviewed a teacher at High Desert who stated that the cooling system was not effective. The teacher stated that at one point, the cooling system broke, and temperatures reached more than 86°F. The hot conditions in the classroom caused him to suffer a heat-related illness. If prisons were required to comply with Cal/OSHA standards, the working conditions described above would be considered unacceptable. The department is aware of its infrastructure challenges, and that the fans and air handling equipment used in its prisons have a useful life of around 20 to 25 years. Prison staff try their best to repair or replace parts to avoid replacing entire systems. High Desert has only had to replace one system since 1995, and it was almost 30 years old at the time. At the three prisons we reviewed for this report (Corcoran, High Desert, and Lancaster), we noted that each prison had some equipment used for heating and cooling that was more than 25 years old. The department is seeking additional funds for a pilot program to evaluate air cooling solutions in a select number of buildings at four prisons. The pilot program, as proposed, called for installing different types of air-cooling alternatives, including installing insulation on exterior walls in 10 housing units at four prisons, and studying the effectiveness of the different cooling solutions put into place. The pilot program’s cost estimate was originally $69 million; however, only part of the request was approved. California’s 31 prisons operate more than 1,500 cooling units, and this pilot program would account for less than one percent of the cooling units statewide. The cost to replace and upgrade the heating and cooling systems in all housing units at all prisons would likely be billions of dollars and take several years to complete—a significant financial investment for the State. This projection is consistent with the LAO’s report that estimated a need for more than $18 billion to maintain and repair what it labeled as significant infrastructure issues in California’s prisons. Recommendations • The department should prioritize replacing heating and cooling equipment that has outlived its useful life and is no longer effective in maintaining temperatures in prison buildings Office of the Inspector General, State of California Return to Contents 22 | OIG Report AUD № 24–02, Management of Temperature Conditions in Prisons and housing units under the current departmental design guidelines, or the guidelines established or agreed upon with other stakeholders. • The department should establish statewide policies and procedures for plant operations staff to effectively track and complete preventive maintenance on heating and cooling equipment to maximize the useful life of these systems. Office of the Inspector General, State of California Return to Contents OIG Report AUD № 24–02, Management of Temperature Conditions in Prisons | 23 Chapter 3. The Department Does Not Protect a Significant Number of Vulnerable Incarcerated Individuals From Heat or Cold Extreme temperatures, whether hot or cold, pose a significant risk to the incarcerated population, especially to those who are more vulnerable due to age or chronic conditions, such as diabetes. While the department has procedures in place to protect those taking specific medications during extreme heat, until this audit, it did not have statewide procedures in place to protect a significant number of the incarcerated population who are vulnerable during temperature extremes of heat and cold.15 The Department Does Not Have Statewide Policies to Protect Most of the Incarcerated Population From Heat Although the department provides some protection from extreme heat under procedures outlined in its heat plan, these procedures only apply to individuals who take certain medications that make them more sensitive to the heat. This small portion of the incarcerated population is approximately 13 percent of the total incarcerated population as of the time of this report. The other 87 percent of the incarcerated population, including those more vulnerable due to age or chronic conditions, are left without such protections. A manager at the department told our auditors that the department tries to protect those who do not fall under the heat plan by training staff to pay attention to anyone displaying or complaining about heat-related symptoms, such as confusion, dizziness, or nausea. While staff may be looking out for anyone displaying heat-related symptoms, it is unclear whether other provisions of the heat plan are applied to incarcerated people who are not taking medications that could make them more sensitive to heat. Correctional officers at two of the three prisons we reviewed told us that the heat plan is not applied across the board to the entire incarcerated population. Although some officers allow cold water, ice, and time out of cells to all incarcerated people during periods of extreme heat, custody staff are not consistent in providing these options. Two officers reported that only the incarcerated individuals who fall under the heat plan receive cold water and ice. The frequency of showers and the amount of ice that can be provided to mitigate against the heat is dictated by staff availability. Although those taking certain medications are more sensitive to extreme heat, studies have shown that heat exposure puts the entire incarcerated population at higher risk of heat-related mortality. These studies have found that prison characteristics, such as physical 15. On March 17, 2025, the department updated its heat plan by expanding its protections to the entire incarcerated population. Office of the Inspector General, State of California Return to Contents 24 | OIG Report AUD № 24–02, Management of Temperature Conditions in Prisons confinement, social isolation, and high rates of chronic mental and physical illness exacerbate an incarcerated person’s vulnerability when exposed to excessive heat. For example, a 2022 Texas study looked at 3,464 deaths of incarcerated people that occurred between the months of May and October when the heat exceeded 85°F in prisons without air conditioning, and found that an average of 14 deaths per year between 2001 and 2019 were associated with heat.16 The study found that most of the deaths were males between the ages of 45 and 62. California’s prison population is aging, with nearly 40 percent of incarcerated individuals over the age of 45. Given that California has several prisons located in the Central Valley and Southern California, both areas that are known to experience periods of excessive heat, the department should implement procedures to protect this population segment. The high temperatures in Corcoran, California, which peaked around 113°F in the summer of 2024, likely led the prison to implement additional procedures to protect its entire incarcerated population during extreme heat. Specifically, in August 2024, Corcoran implemented heat-mitigation measures during periods of extreme heat that exceeded the measures provided for in the heat plan and applied these measures to its entire population. Following the stages of the heat plan, Corcoran committed to providing insulated coolers filled with cool water in dayrooms when the heat alert reached Stage I level. At Stages II and III, Corcoran committed to providing access to additional showers, and access to cooling stations in areas such as facility dayrooms, chapels, education classrooms, and committee rooms. In addition, incarcerated people were allowed access to recreational yards while the water sprinklers were in use, and cell doors were allowed to be open during normal program hours in general population housing units to improve air flow. Considering the vulnerabilities of the incarcerated population in general, the high number of vulnerable individuals in California’s prisons, and the extreme temperatures where the prisons are located, we question why more prisons, including Lancaster, which endured 60 days of temperatures 100°F or higher in 2024, have not implemented more expansive heat mitigation measures like those taken at Corcoran in 2024. The department should consider a broader policy that protects the entire population when exposed to extreme heat events, not only individuals covered by the heat plan. The Department Could Provide Additional Measures to Protect the Incarcerated Population at Prisons From Cold Weather Although more incarcerated people complain about hot temperatures in prisons, extreme cold temperatures also impact the incarcerated 16. Provision of Air Conditioning and Heat Related Mortality in Texas Prisons (November 2, 2022). Office of the Inspector General, State of California Return to Contents OIG Report AUD № 24–02, Management of Temperature Conditions in Prisons | 25 population in California. For example, five prisons in California experienced 100 or more days of temperatures below 40°F in 2024. The OIG reviewed complaints the department received between August 2022 and July 2024 about living conditions. The OIG filtered the complaints to focus on those related to hot and cold conditions. To understand seasonal differences, the OIG sampled complaints submitted in August 2022 and January 2024. In January 2024, Corcoran received 36 complaints about cold temperatures according to the samples reviewed by the OIG. Corcoran experienced temperatures as low as 30°F during the winter of 2024. Most individuals can find relief from the cold by putting on additional clothing such as a jacket, but not all prisons offer sufficient clothing for incarcerated people to protect themselves from the cold. The department provides all male incarcerated individuals one denim jacket as part of the standard clothing issued to them. However, these denim jackets are thin and do not provide sufficient warmth for cold temperatures. The department also offers an additional thicker, lined polyester jacket and permits prisons to provide the thicker jacket to those who work outdoors in inclement weather on a regular basis. Departmental policy does not require prisons to offer the thicker jacket to all incarcerated people, but some prisons have offered a thicker jacket. The department leaves this decision to the discretion of each prison. Based on our findings, the department should consider providing the incarcerated population with additional clothing options. For example, at High Desert and Lancaster, incarcerated people are offered the thicker jacket. We also noted that these two prisons received fewer complaints concerning the cold temperatures. However, at Corcoran, all incarcerated people receive the thin denim jacket, unless they have an outdoor work assignment. As noted above, Corcoran received a high number of complaints about cold temperatures. One incarcerated person we interviewed at Corcoran stated that even inside in his cell, he can see his breath during winter months. Although the department allows incarcerated people the option to purchase a thicker jacket, many incarcerated people cannot afford the cost of the thicker jacket. Considering that a thicker jacket can help preserve body heat, which can help mitigate or prevent many health problems caused when body temperature drops, the department should consider offering incarcerated people the option to choose between having access to the denim jacket or the warmer, thicker jacket to prevent adverse health effects deriving from cold temperatures. Office of the Inspector General, State of California Return to Contents 26 | OIG Report AUD № 24–02, Management of Temperature Conditions in Prisons Recommendations • The department should consider expanding heat plan measures for all incarcerated people to protect vulnerable individuals in an aging population. • The department should consider providing the incarcerated population the option of receiving a thicker jacket to protect individuals during cold weather. Office of the Inspector General, State of California Return to Contents OIG Report AUD № 24–02, Management of Temperature Conditions in Prisons | 27 Appendix Scope and Methodology California Penal Code section 612(b) and (c) authorizes the OIG to initiate audits of the department’s policies, practices, and procedures. This audit focuses on the department’s operational processes for mitigating extreme temperatures within the institutions to keep the incarcerated population in a safe and humane environment. It also focuses on meeting certain standards set forth in the California Correctional Health Care Services (CCHCS) Heat Plan and the departmental Design Criteria Guidelines, and the ways in which institutions aim to meet these standards. The table below presents the objectives of our audit and the methods we used to fulfill them. We conducted this performance audit in accordance with generally accepted U.S. federal government auditing standards. Those standards require that we plan and perform the audit to obtain sufficient, appropriate evidence to provide a reasonable basis for our findings and conclusions according to our audit objectives. We believe that the evidence we obtained provided a reasonable basis for our findings and conclusions. Office of the Inspector General, State of California Return to Contents 28 | OIG Report AUD № 24–02, Management of Temperature Conditions in Prisons A–1. Audit Objectives and Methodology Audit Objectives Method 1. Review and assess the A. We reviewed relevant laws, rules, regulations, policies, and procedures department’s processes, related to the CCHCS Heat Plan and the departmental design guidelines policies, and procedures for maintaining indoor temperatures. for handling excessive temperatures to determine B. We received and reviewed the following information: their adequacy for preventing, • Design Criteria Guidelines for departmental prisons, timely detecting, and • Department Operations Manual and Local Operating Procedures, responding to health-related concerns the incarcerated • Copies of the CCHCS Heat Plan, population or staff could • Cal/OSHA Regulations–8 CCR § 3395, 8 CCR § 3396, and suffer due to excessive temperatures. • Departmental policy for staff training to comply with the heat plan. C. We developed testing around the Design Criteria Guidelines for the period of August 1, 2022, to October 31, 2023; we also applied our testing to Cal/OSHA standards and standards used in jails in the State of Texas. 2. Determine whether the A. We conducted on-site observations at three prisons: California State department has adequate Prison, Corcoran (Corcoran), California State Prison, Los Angeles County processes in place to (Lancaster), and High Desert State Prison (High Desert) effectively operate during • We performed walk-throughs with plant operations staff at two excessively high or low prisons to gain an understanding of the infrastructure they have in temperatures. place to manage extreme temperatures and any challenges they may face in meeting the design criteria guidelines. B. We interviewed plant operations staff at the three sampled prisons to understand • If prison buildings meet design criteria guidelines, • If plant operations staff conduct preventive maintenance on their equipment and how often it is completed, and • What role plant operations staff have in the bidding process for new equipment. C. We interviewed plant operations staff at the three sampled prisons to understand • If prison buildings meet design criteria guidelines, • If plant operations staff conduct preventive maintenance on their equipment and how often it is completed, and • What role plant operations staff have in the bidding process for new equipment. D. We interviewed plant operations staff at the three sampled prisons to understand • If prison buildings meet design criteria guidelines, • If plant operations staff conduct preventive maintenance on their equipment and how often it is completed, and • What role plant operations staff have in the bidding process for new equipment. (Continued on next page.) Office of the Inspector General, State of California Return to Contents OIG Report AUD № 24–02, Management of Temperature Conditions in Prisons | 29 A–1. Audit Objectives and Methodology (continued) Audit Objectives Method E. We interviewed plant operations staff at the three sampled prisons to understand • If prison buildings meet design criteria guidelines, • If plant operations staff conduct preventive maintenance on their equipment and how often it is completed, and • What role plant operations staff have in the bidding process for new equipment. F. We interviewed correctional officers and departmental staff at each of the Corcoran and High Desert prisons to understand • What the temperature conditions are like in the housing facilities throughout the year, • The correctional officer’s role in helping to mitigate extreme temperatures, and • How the prison as a whole handles extreme temperatures. G. We interviewed the Inmate Advisory Council (IAC) at the three sampled prisons to understand • The temperature conditions in the housing units and cells throughout the year, • How prison staff manage excessive temperatures, and • If complaints regarding temperature are timely resolved by the prison. H. We interviewed heat plan litigation coordinators at each sampled prison to understand their responsibilities for processing and completing the heat logs. I. Auditors tested preventive maintenance and work orders at Corcoran and High Desert. • High Desert tested between March 15, 2023, and October 31, 2024. • Corcoran tested between July 5, 2023, and October 31, 2024. 3. Assess whether the A. For the three prisons we selected for testing, we completed the following: department follows their • Reviewed and analyzed staff training documents to determine if staff established procedures received training for the CCHCS Heat Plan, and for managing excessive temperatures. • Determined if prison staff at the three prisons properly completed CCHCS heat logs for the period of August 1, 2022, through October 31, 2024. B. Determined if the temperatures staff recorded in CCHCS heat logs were within departmental design guide criteria, Cal/OSHA guidelines, and the State of Texas jail standards. C. Determined if the three prisons complied with any applicable local operating procedures regarding the CCHCS Heat Plan. D. Interviewed prison staff and incarcerated people at each of the three sampled prisons to identify any additional measures used to mitigate temperatures in housing units. Source: Compiled by OIG auditing staff. Office of the Inspector General, State of California Return to Contents 30 | OIG Report AUD № 24–02, Management of Temperature Conditions in Prisons Assessment of Data Reliability The U.S. Government Accountability Office, whose standards our office follows in performing and preparing audits, requires us to assess the sufficiency and appropriateness of computer-processed information that we use to support our findings, conclusions, or recommendations. In performing this audit, we relied on the department’s heat log records. To evaluate this data, we reviewed existing information about the data and interviewed staff members knowledgeable about the data. While on-site, auditors observed thermometers used to inform the heat logs. The heat logs were not found to be reliable sources due to their having days of missing entries that prison staff had not appropriately recorded. Therefore, heat logs should be used for informational purposes only. The OIG could not test the data on the number of housing units provided by the department; therefore, it should also be used for informational purposes only. In addition, during interviews with the department, staff informed us that equipment maintenance data is entered manually into the software and is not always current. The department implemented new equipment maintenance software in 2023. For this reason, the equipment maintenance data should also be used for informational purposes only and should not be relied upon for audit purposes. Office of the Inspector General, State of California Return to Contents OIG Report AUD № 24–02, Management of Temperature Conditions in Prisons | 31 The Department’s Response to Our Report Docusign Envelope ID: 4E842A5D-2AAB-4A62-AAF3-8E7F4EE98AB3 STATE OF CALIFORNIA — DEPARTMENT OF CORRECTIONS AND REHABILITATION GAVIN NEWSOM, GOVERNOR OFFICE OF THE SECRETARY PO Box 942883 Sacramento, CA 94283-0001 September 10, 2025 Ms. Amarik Singh Office of the Inspector General 10111 Old Placerville Road, Suite 110 Sacramento, CA 95827 Dear Ms. Singh: The California Department of Corrections and Rehabilitation (CDCR) has reviewed the draft report titled Audit of the California Department of Corrections and Rehabilitation’s Management of Temperature Conditions Within California’s Prisons. The Department is committed to maintaining safe and humane conditions for all individuals in our custody and all staff in the institutions and acknowledges the oversight in this area is important. CDCR recognizes the critical need to advance efforts to manage indoor temperatures across housing units. CDCR has initiated efforts to address this issue, though full implementation will require time and dedicated funding. As part of its ongoing commitment to improving facility conditions, the Department has recently completed cooling upgrades at Ironwood State Prison and on Facility A at the California Institution for Men. These improvements mark an important step forward in the Department’s broader strategy to enhance infrastructure and promote safe, humane environments for the incarcerated population and the staff. The Department acknowledges indoor temperature standards are evolving and recognizes the need to update its own policies to reflect these changes. As part of the Department’s broader commitment to safe and climate-resilient correctional environments, CDCR is initiating a three- year pilot program to explore effective strategies for managing indoor temperatures across its institutions. This will involve installing improved cooling and insulation options on two housing units at Kern Valley State Prison, California State Prison Los Angeles County, and the Central California Women’s Facility (CCWF). This pilot intends to map out future options using all available means to address indoor temperatures. The Department’s plan includes developing broader solutions for facilities where upgrades may be necessary throughout the pilot. Cooling will also require significant upgrades to the underlying infrastructure. In the interim, the Department is examining ways to address existing cooling systems that are failing. For example, two housing units at CCWF recently had their outdated evaporative cooling systems replaced with hybrid evaporative/mechanical units, which have demonstrated improved performance and cost-efficiency in the short term. The Department is committed to taking meaningful steps toward improving indoor temperatures across its institutions and is actively engaged in this effort. CDCR is studying the complexity of Office of the Inspector General, State of California Return to Contents 32 | OIG Report AUD № 24–02, Management of Temperature Conditions in Prisons The Department’s Response to Our Report (continued) Docusign Envelope ID: 4E842A5D-2AAB-4A62-AAF3-8E7F4EE98AB3 Amarik Singh, Office of the Inspector General Page 2 the problem and creating new solutions within limited fiscal constraints as we move forward to address temperatures. We appreciate OIG’s findings and are committed to identifying responsive strategies within the scope of available authority and funding. We look forward to engaging with stakeholders as we move forward with this effort over the next several years. If you have any questions, contact me at (916) 323-6001. Sincerely, JEFF MACOMBER Secretary Office of the Inspector General, State of California Return to Contents Audit of the California Department of Corrections and Rehabilitation’s Management of Temperature Conditions Within California’s Prisons Audit Report № 24–02 OFFICE of the INSPECTOR GENERAL Amarik K. Singh Inspector General Shaun Spillane Chief Deputy Inspector General STATE of CALIFORNIA September 2025 OIG