• Posted March 5, 2024

Dangerously Hot, Humid Conditions Common in U.S. Prisons

Almost 2 million Americans incarcerated in the nation's jails and prisons suffer through an average 100 days per year of dangerous heat and humidity, a new report finds.

A warming world will only increase that danger, say researchers at Columbia University in New York City and elsewhere.

"Exposure to excess heat and humidity can lead to deadly heat stroke and kidney disease from chronic dehydration, among other health issues, for incarcerated people in the United States," explained study lead author Cascade Tuholske, an assistant professor of human-environment geography at Montana State University in Bozeman.

Senior study author Robbie Parks said common attitudes toward prisoners are allowing these inhumane conditions to continue.

"Dangerous heat impacting incarcerated people has been largely ignored, in part due to perceptions that their physical suffering is justified," Parks said in a Columbia University news release. He's an assistant professor of environmental health sciences at Columbia.

In the study, Tuholske, Parks and colleagues used available data to estimate heat and humidity at almost 4,100 incarceration facilities nationwide.

Looking at data for 2016 to 2020, they calculated the number of days with a "wet bulb globe temperature" (a measure of stress caused by heat-plus-humidity) that exceeded 82.4 degrees Fahrenheit.

That's a threshold set by the U.S. National Institute for Occupational Safety and Health, aimed at limiting unhealthy humid heat exposures, the researchers explained.

They found that approximately 1.8 million incarcerated people in the United States now suffer from excessive "wet bulb" conditions for an average of 100 days per year.

Many of these prisoners are housed in one of the 44 states that do not mandate universal air conditioning to prisoners.

Prisoners in two southern states, Florida and Texas, comprised over half (52%) of those subjected to excessive heat/humidity, the researchers noted.

"An estimated 118 carceral facilities -- largely in southern California, Arizona, Texas, and inland Florida -- experienced on average 75 days or more per year of dangerous humid heat," the Columbia news release stated.

Prisoners at one facility -- the Starr County Jail in Rio Grande, Texas -- experienced an average 126.2 days per year of dangerous humid heat. That was the highest recorded over the four-year study.

What's more, prisons tend to cluster in hotter regions. According to the study, areas with prisons experienced 5.5 more days per year of dangerous humid heat versus places without prisons.

The findings were published March 5 in the journal Nature Sustainability.

The problem is only getting worse: Almost 916,000 incarcerated people (45% of the total U.S. prison population) are housed in facilities where the number of dangerously hot, humid days per year is on the rise, the study found.

Compared to non-incarcerated Americans, prisoners also tend to have a higher odds of health conditions that make them vulnerable to humidity and heat. That includes mental health conditions, Parks and Tuholske noted, because being on psychiatric meds up the odds for heat illness.

Hot, humid conditions in prisons happen nationwide. However, "the majority of these exposures are happening in state-run prisons and jails in Southern states that do not legally mandate access to air conditioning for the incarcerated," Tuholske said.

"It is concerning because climate change is amplifying dangerous heat extremes in these locations," he added.

Legislative change that brings more humane conditions to prisons is needed, Parks believes, but prisoners have few means of advocating for themselves.

 "Laws mandating safe temperature ranges, enhanced social and physical infrastructure, and focused health system interventions could mitigate the problem," he said. "Doing so is critical for incarcerated people, who have severely limited social and political agency."

More information

Find out more about the effects of heat and humidity on health at the UC Davis Environmental Health Sciences Center.

SOURCE: Columbia University Mailman School of Public Health, news release, March 5, 2024