Air conditioning broke in our workspace, coworker passed out and they’re being blamed

I work in a medical diagnostic laboratory which requires all employees wear lab coats over our clothes, in addition to long pants and covered shoes at all times. Our air conditioning broke months ago and they have been “working on it”. It was bearable for awhile, but now that it is summer, temps have reached 85-95 degrees Fahrenheit daily. We have expressed concern for these working conditions, which are met with suggestions from higher ups such as “take a 5 minute break” and “stay hydrated”.

A coworker of mine passed out in the lab recently when the temp was 85F. They were taken to the hospital and treated for a concussion. Higher ups and the safety officer immediately blamed the coworker for working too much and refused to acknowledge the heat. Another employee suffered dehydration this past Friday while working, and had to be taken to the hospital to get an IV.

I’ve searched, but I can’t find anything directly stating what a workspace temperature should be. I’m not sure if I can report this or even where to. Any ideas?