Extreme heat due to climate change is already turning some U.S. prisons into “microwaves where prisoners bake between metal walls and bars with little air-conditioning relief,” Grist and Climate Desk report, based on a study by Columbia Law School’s Sabin Center for Climate Change Law.

“The correctional sector may be alone in facing the prospect of viable constitutional litigation if it does not effectively adapt to the changing climate,” the study states.

With more than two million people “caged in our prison system,” Mock writes, “there is no population more captive to the effects of global warming than the incarcerated. And given the huge concentration of black and Latino prisoners in America, this is a classic case of environmental injustice, as these consequences fall widely on prisoners of colour.”

Some U.S. courts have ruled that extreme heat in prisons counts as cruel and unusual punishment. Other cases have considered whether overheating is an Americans with Disabilities Act violation for inmates with heat-related ailments.

The Columbia study notes that tempers can be expected to rise with the thermometer, and unresolved overcrowding makes the problem even worse.

“Heat in prisons has implications for both health and security, of inmates and correctional officers alike: the potential for increased violence,” the report states. “Fighting among inmates and assault incidents may increase when high temperatures cut tempers short.”

Moreover, since “human beings are sources of heat and humidity, the number of people in a given enclosed space has a direct impact on the thermal conditions in that space. Therefore, overcrowding of correctional facilities is an impediment to maintaining a tolerable interior environment.”