by Matt Clarke

The California Department of Corrections and Rehabilitation (CDCR) recently announced a pilot program to study the use of various types of cooling systems and new insulation at three prisons to determine the best methods for wider application within its 31-­prison system. Currently, only around 8,000 (8.8%) of the CDCR’s 91,000 prisoners are incarcerated in cooled living locations. Results from the pilot program will likely become available in mid-­2029.

For years, prisoners complained of brutal heat in California’s prisons and advocates lobbied for cooling, only to be ignored by state lawmakers and the CDCR. But recent lawsuits against the CDCR and the success of similar legal action in other states have motivated both to reevaluate the agency’s longstanding claim that heat is not a problem in California’s prisons.

“Extreme heat poses a serious health risk to all in CDCR,” said senior attorney Lilly Harvey of the Prison Law Office, an organization that represents prisoners in several class-­action lawsuits over heath care in CDCR. “Air-­conditioned housing units are the only effective way to protect against that risk.”

CDCR officials disagree. They claim that prisons in more temperate zones might not need air conditioning and estimate the cost of “statewide implementation of effective cooling mechanisms” at $6 billion without providing any breakdown showing how they arrived at such an exorbitant figure.

This brings to mind Texas prison officials’ estimate of $200 million to air condition a single prison, the Pack Unit, when the actual costs were closer to a tenth of that amount. The math is easy. If it costs $38 million to cool three prisons, it should cost around $355 million to cool the remaining 28 prisons. That is less than 6% of the CDCR estimate.

The pilot program will test using air conditioning, insulation, or a combination of both to keep indoor temperatures at 78 degrees Fahrenheit (26 degrees Celsius) or lower. Heat becomes a health risk when the heat index (heat adjusted for humidity) exceeds 87 Fahrenheit (30.6 degrees Celsius).

The design of many prisons causes their indoor temperatures to exceed the ambient outdoor temperature. The uninsulated materials most prisons are made of—thick brick walls or huge concrete slabs—tend to absorb a great deal of radiant energy from the sun and only slowly dissipate it after nightfall. Thus, many prisoners in California and other states experience temperatures that put health at risk well into the summer nights.

During 2024, at least one California prison experienced outdoor temperatures exceeding 90 degrees Fahrenheit (32 degrees Celsius) on 182 days. For 86 days, at least one prison had indoor temperatures exceeding 90 degrees Fahrenheit (32 degrees Celsius) and exceeding 95 degrees Fahrenheit (35 degrees Celsius) indoors on 46 days.

CDCR officials claim they have a court-­mandated “successful protocol” used to monitor the prisoners most at risk of heat illness. It requires staff to monitor indoor and outdoor temperatures from May until October and move at-­risk prisoners indoors and monitor them for signs of heat stoke every few hours on the hottest days. However, Matthew Lopez, a monitor appointed by a federal court, found that staff at half of the 14 prisons he toured were unaware of the protocol. He questioned the accuracy of temperature logs at three prisons and found broken or missing thermometers at two. Lopez also reported that some prison officials “’commendably’ go out of their way to ease conditions during heat waves…[and] others are ‘failing to approach compliance.’”

After three prisoners died of hyperthermia in their cells at the California Medical Facility in 1991, CDCR instituted its current protocol. The protocol has three stages. An outdoor temperature of 90 degrees Fahrenheit (32 degrees Celsius) triggers Stage One, which requires that heat-­sensitive prisoners be moved indoors. An indoor temperature of 90 degrees Fahrenheit (32 degrees Celsius) triggers Stage Two, giving those prisoners access to showers and ice. Stage Three is triggered by an indoor temperature of 95 degrees Fahrenheit (35 degrees Celsius) and requires medical personnel to check at-­risk prisoners for signs of heat stroke every two hours. One fault in this protocol is that indoor temperatures are measured in common areas, which can be as much as 21 degrees Fahrenheit (12 degrees Celsius) cooler than the uninsulated and poorly ventilated concrete cells that many prisoners are assigned to.

Another problem with the protocol is that its implementation depends upon which staff member is on duty and whether they know or care about following it. In addition to Lopez’s observations, there is evidence that staff at some prisons are not concerned with heat—they fail to fill out the heat logs that are at the heart of California’s protocol system, or they falsify entries in the heat logs as evidenced by them having the same temperature for every entry over a three-­day period at one prison.

California prisoners are permitted to keep a personal fan in their cells. It costs around $27 in the prison commissary. A prisoner working in the lowest paid prison job would need about 4 weeks of wages to pay for a fan.

When Lawrence Cox was a prisoner incarcerated at the California State Prison in the Imperial County desert and California State Prison Solano in Vacaville, he had to wet his bedsheets in the sink to try to keep cool in his poorly ventilated cells. This raised the humidity in the cells and left him with permanent marks on his skin from heat rashes. Now released, he is an advocate with Legal Services for Prisoners with Children. “I have never sweated so much, continuously, all day, just simply sitting there,” Cox told the news outlet CalMatters. “There’s really no reprieve.”

Every summer, many of the 2,000 women incarcerated at the Central California Women’s Facility in Chowchilla, as CalMatters reported, “flood the phone lines of community advocacy groups and attorneys’ offices, raising alarms about hot conditions…Every summer from 2020 through 2024, Chowchilla saw at least seven days that reached or surpassed 105 degrees, and the summer of 2024 “set a record at 28 days.”

That’s when Chowchilla prisoner Adrienne Boulware, who was prescribed the heat-­sensitive medication lithium, died after being taken to a hospital suffering from heat stroke. Upon arrival, her body temperature was measured at 106.7 degrees Fahrenheit (41.5 degrees Celsius).

CDCR officials claim Boulware’s death was unrelated to heat, leaning heavily on the fact that fentanyl was found in her blood. However, days after her death, one of CDCR’s own medical workers listed the loss of consciousness and seizures she was experiencing as due to “heat stroke and possible overdose” and the CDCR officials who notified her family that she had been taken to a hospital said it was due to heat stroke.

Boulware’s case illustrates one of the problems with determining how many prisoners died of excess heat. As with Boulware, heat can exacerbate other conditions and is rarely listed as the sole cause of death even if, absent the excess heat, the person might still be alive. This allows CDCR to claim it has experienced only a few “sentinel events” of prisoners dying due to heat.

That claim, however, is questionable as a peer-­reviewed study published by PLOS One in 2023 showed that mortality rates in state and private prisons increased by 3.5% on extreme heat days and by 7.4% during three-­day heat waves. This shows heat can be a significant factor in causing prisoner deaths regardless of what is listed as the official cause or causes of death. Another problem is the alleged expense of controlling temperatures in the state’s prisons.

California’s Occupational Safety and Health Administration recently began requiring workplace temperatures to be kept below 87 degrees Fahrenheit (31 degrees Celsius) but prisons were exempted because it would cost too much to comply under the CDCR’s fantastical estimates. Hence, both prisoners and CDCR staff continue to be exposed to dangerous temperatures.

Although 44 states have prisons that are not fully air conditioned in all prisoner housing areas, recent court case in which prisoners successfully challenged life-­threatening heat have given momentum to the move for universal prison air conditioning. The most noteworthy recent court opinion is Tiede v. Collier, 2025 U.S. Dist. LEXIS 168326 (W.D. Tex. 2025), which involved a systemwide challenge to a lack of air conditioning in the Texas Department of Criminal Justice (TDCJ); that case itself was built on the success of TDCJ prisoners from a single prison in achieving a favorable settlement, Cole v. Collier, 2017 U.S. Dist. LEXIS 112095 (S.D. Tex. 2017), after the court of appeals affirmed their position in Yates v. Collier, 868 F.3d 354 (5th Cir. 2017). The Tiede court ruled that the extreme heat in Texas prisons is “plainly unconstitutional.” [See: PLN, May 2025, p. 7].

Texas began housing heat-­vulnerable prisoners in air conditioning even before the Tiede suit was filed, having seen the writing on the wall after its loss in Yates. Although TDCJ has retrofitted air conditioning in a few prisons, many of those prisoners were and are being housed in former administrative segregation and “superseg” housing that was not designed to house general population prisoners and is incapable of providing the requisite amount of dayroom and recreational space for them. [See: PLN, Sept. 2023, p. 1].

That trend has been recently aggravated by TDCJ adding a second bunk to the previously single-­bunk segregation cells, doubling the pod occupancy without any increase in the already-­inadequate dayroom and rec space. TDCJ touts this as “procuring” new air-­conditioned housing, but it is actually just jamming more people into already existing housing.

In addition to the efforts in California and Texas, North Carolina prison officials continue to work toward their goal of air conditioning all 54 state prisons. So far, 33 are completely air conditioned and 17 are partially air conditioned.

Prisoners have filed federal civil rights lawsuits challenging extreme heat in most of the states lacking universal prison air conditioning. Most are pro se and doomed to fail due to a lack of resources or litigation experience but some, like the Texas case, are backed by large advocacy groups with adequate resources and representation, giving them a much greater likelihood of success. One such effort is in Missouri, where the nonprofit MacArthur Justice Center filed a class action in May 2025 with six prisoners at the nearly century-­old Algoa Correctional Center as named plaintiffs.

Elsewhere, Delaware included $2 million in its FY 2026 budget to cover the cost of installing air conditioning at the James T. Vaughn Correctional Center. And in 2025, Virginia lawmakers passed a bill requiring the state’s prison system to install heating and air conditioning in all of its prisons; then-­Governor Glenn Youngkin (R), however, vetoed it citing the cost of installation and operational burdens. Youngkin said at the time that the data from the prison system “does not substantiate the claims of extreme heat or health risks.”

Prison staff are largely ignored in the debate over air conditioning prisons in most states.

“There are people working in prisons and the have the right to work in climates that are comfortable,” according to Nancy La Vigne, a Rutgers University School of Law criminal justice researcher. “When they’re not, there’s retention issues, and it’s hard to replace staff. And when you don’t replace staff, then you have challenges in maintaining the safety and security of the facility.”

La Vigne’s point is driven home by the three-­week New York prison staff strike in 2025. During the strike, many guards found that there were more comfortable places to work, so they simply chose not to return to work when the strike ended, causing some prisons to operate understaffed by 30 to 60%. This highlights why staff retention, the root of many problems in most of America’s prisons, could also be improved by universal prison air conditioning. 

Sources: CalMatters, Florida Phoenix

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