Heat has killed hundreds of workers in the U.S., many in construction or agriculture, an investigation by NPR and Columbia Journalism Investigations found. Federal standards might have prevented them.

As a hotter climate reshapes American lives, it also threatens them, especially on the job. The weapons against heat illness are seemingly simple, from more water to rest breaks, but standards, enforcement and training are often lacking to ensure protection.

California is seen as a nationwide leader in hot weather protections, but its workers are still getting sick and dying from heat. Experts and insiders say climate change and a dysfunctional Cal/OSHA are to blame.