I worked in a factory without air conditioning last summer, during the worst heat wave in literally 50 years.
Up in the north we ain't use to no heat, 25 degree's is crazy hot to me, and it was 40-50 degrees with the humidex for the whole summer inside that factory.
That by itself wouldn't of been an issue, but being 6 4 in a factory made for midgets with tendon issues in both my arms and nerve damage, it's fucking brutal.
Every 8 hours was hell, and I did quite a bit of permanent damage to my body.
Seriously if you don't go home at the end of the day, knowing you've done serious damage to your body you've never worked in my opinion.