A state board recently voted unanimously to create long-awaited indoor heat standards for California workers. After a final legal review, that will mean protections for millions of people with jobs in warehouses, kitchens and other workplaces that are getting dangerously hot as the climate warms. The board made one glaring exception, however — for prisons and jails.

The state Department of Finance had withdrawn its support for the standards just as they were about to be approved in March, noting that the rules would cost prisons and jails billions of dollars. To salvage the regulations, the California Division of Occupational Safety and Health, known as Cal/OSHA, excluded such facilities from the standards. Opponents of the standards point to the high costs associated with installing and running cooling systems, offering workers more breaks and other ways of adapting to heat.

And adapting to climate change is indeed costly. So excluding prisons and jails may seem like a straightforward, pragmatic way to cut the cost of regulations that will undoubtedly be expensive anyway. Research has suggested, however, that the regulations could save up to $875 million annually by preventing heat-related injuries among California workers.

And the threat is only growing more urgent: Last summer was the hottest on record, and this one might prove even hotter. Extreme heat kills more people than all other extreme weather events or natural disasters, though these deaths are often hard to rec.