In india, I lived in maximum 50 degree Celcius
I was in 39C heat once when I was down south at Canada's Wonderland. That was brutal. I'll take -40 before +40. Anything above 30 is just too much. It's the constant sweating that makes it bad. 40 was also very nauseating. Way way way too hot.
I've had to call out hvac techs to some of our buildings where the AC failed and the temp started to climb. I've seen some buildings hit 50+ degrees, I'd hate to be the tech having to go work in there. Pretty much have to open the door, put fans, let it cool off a bit, before being able to do anything. That's typically what they'll do if the work has to be done inside. just touching anything metal will practically burn you so hard to work on equipment without letting it cool off. Like touching the seat belt in a hot car.