exacerbated the risks, including overcrowding and restrictions on movement.

Another study published in the National Library of Medicine found that hotter days mean more deaths from such things as heart disease and suicide - including among people who had been incarcerated for less than a year and those who were 65 or older.

(AP Photo/Ellen Schmidt)

Julie Skarha, who led the study on prison deaths linked to hotter days, said newly incarcerated people had a higher risk of dying, likely because they are not yet acclimated to the heat.  Some people are sentenced to serve in places they've never lived before. ... So suddenly, someone is having to adapt to this environment very quickly, something they're not used to,  she said.

 It's absolutely stifling. You can't breathe'

In the Minnesota prison at Lino Lakes, about 336 prisoners live in two medium-security units built in 1992 that the state acknowledges do not have effective cooling.

Greg Andreotti, who spent two summers in both units, said the facility's design can exacerbate the heat. The cells hold up to two people and have large windows, and when Andreotti was there, they had no tinting or reflective film,  so your room bakes all day in the sun. 

Inside the prison, people can buy small personal fans currently priced at $27.53, but many cannot afford them, he said. Other times they were not in stock. And while they might bring some relief, research shows fans are ineffective during heat waves.

The Minnesota Department of Corrections said those two housing units did not originally have air conditioning except for in common areas. It was added years later but struggles to control humidity during certain times of the year.

Aaron Swanum, a spokesman for the department, said in an email that there have been multiple repair efforts over the years but  they have not been able to effectively cool the housing units because the system is undersized for the space.  The department is determining ways to better control inside temperatures and anticipates seeking state funding to make improvements.

For now, the facility uses large industrial fans in common areas and in the housing unit hallways, allows continuous access to ice, has painted skylights and takes other measures to help mitigate heat, the agency said. A recently completed window tinting project is expected to help.

 It's oppressive. It's like sitting in a tomb/sauna,  recalled Josh Mcmillen, who was incarcerated in one of Lino Lakes' housing units without effective cooling.  You already feel like you're being entombed when you shut that door. But when you shut that door, and it's absolutely stifling, you can't breathe. You feel no airflow. 

In California, the Department of Corrections and Rehabilitation said it follows a heat illness prevention plan and that each prison monitors temperatures and provides additional cooling measures - including increased access to water stations, ice, showers and fans - during extreme heat.

Without adequate AC, cooling options are limited

Andreotti would cool off in the shower, use wet rags and sometimes lay on the concrete floor. Ice was only available outside his cell, and access was limited.

 When you've got 200 people attacking an ice machine over a three-hour period that you're allowed out of your room, what do you think happens to it? There's no ice,  he said.

Mcmillen would stock up on aspirin for the tension headaches he would get from the heat.

In recent years, lawsuits related to heat in prisons have been filed in states including Missouri, Florida and Texas, where a federal judge called extreme heat in Texas prisons  plainly unconstitutional  and recently ordered the state to install air conditioning in all of its prisons by the end of 2029. Advocates allege temperatures inside can push above 120 degrees Fahrenheit (48.9 degrees Celsius), resulting in hundreds of inmate deaths in recent years.

On a summer day in 2023, Carlos Ramirez Bibiano was found vomiting and covered in a puddle of his own excrement in an outdoor cell in a Georgia prison, according to a lawsuit settled with his family recently for $3.25 million. He was left for five hours without water, shade or ice as temperatures climbed to 96 degrees Fahrenheit (35.6 degrees Celsius), and he was on medications that make it more difficult to regulate body temperature. That evening, the complaint says, Ramirez died of heart and lung failure caused by heat exposure.

Experts say more information, regulation is needed

It's not much better for the prison guards and staff - though they get to go home after their shifts.

Lino Lakes Prison Warden Eddie Miles said they ensure prison staff have cold water, breaks and opportunities to cool off in climate-controlled areas to beat the heat.

Some states have rules to protect workers from extreme temperatures, but those do not apply to inmates. States like North Carolina, Vermont and Texas are spending millions to upgrade or install cooling systems. California says it could cost billions to make changes, though they might save millions in healthcare costs related to heat illnesses.

States have the power to protect inmates from the threat of extreme heat, experts said. It's just a matter of political will.

 It's going to take funding. It's going to take attention and investment and collaborations between those agencies and the experts who are wanting to engage in this issue,  said Carlee Purdum, assistant professor at the University of Houston who studies how disasters impact vulnerable people.