Academic Research · Plain-language review
Hazardous Heat Exposure Among Incarcerated People in the United States
This nationwide study maps a quiet but growing danger: incarcerated people are increasingly confined in places exposed to potentially hazardous heat, while having little control over ventilation, cooling, water access, or movement.
What the researchers studied
The research team estimated potentially hazardous heat exposure for 4,078 operational and populated prisons, jails, immigration detention centers, and other carceral facilities across the continental United States. It combined facility-location and population information with high-resolution climate data covering 1982–2020.
The researchers used wet-bulb globe temperature, a measure that incorporates heat and humidity, and counted days exceeding a threshold used by the National Institute for Occupational Safety and Health for acclimated people doing moderate work.
What they found
Texas and Florida accounted for an estimated 52% of total exposure despite holding approximately 12% of the incarcerated population included in the comparison. Many of the most heavily exposed facilities were in Texas, Florida, Arizona, and Louisiana.
Why this matters to IWP
Unlike people living freely in the community, incarcerated people generally cannot leave an overheated building, choose different housing, obtain their own cooling equipment, or independently change institutional rules. The study therefore belongs within conversations about health, dignity, correctional infrastructure, environmental justice, and public policy.
What the study does not prove
The analysis estimates potential exposure from climate, facility-location, and population data. It did not directly measure the temperature inside every housing unit and did not track individual medical outcomes. It identifies the scale and geographic pattern of potential heat exposure; it should not be read as proof that heat caused a particular illness at every facility.
This limitation also points toward the next work required: reliable indoor-temperature monitoring, transparent cooling information, health-outcome research, and evaluation of practical protections.
Access, transparency, and reuse
The full article, methods, peer-review acknowledgement, supplementary information, source data, and reproducible code are publicly accessible. The article is published under a Creative Commons Attribution 4.0 International licence, permitting use and adaptation with appropriate credit.
Suggested citation:
Tuholske, C., Lynch, V. D., Spriggs, R. et al. “Hazardous heat exposure among incarcerated people in the United States.” Nature Sustainability 7, 394–398 (2024). https://doi.org/10.1038/s41893-024-01293-y
Read alongside
This study maps how widespread hazardous heat exposure may be. The JAMA Network Open study already in the IWP library examines a related question: the association between extreme heat and recorded suicide-watch incidents in six Louisiana prisons. Together, the papers show how environmental exposure and mental wellbeing can be studied at different levels.
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