A funny thing happens to those who live or train in extreme environments, their body adapts over time. You or I might pass out if we were suddenly exposed to that sort of factory environment, but an experienced worker might handle limited exposure just fine. The human body is amazingly adaptable.
Nah, that will literally kill any human in potentially minutes. No one can heat adapt to 100F + 95% relative humidity. It literally will cook you dead.
Not at all. I've spent plenty of time (sessions exceeding an hour) in saunas that were >105F and >95% humidity (literally so much steam that it was continuously raining from the condensation).
Remember that when you get a fever, your internal body temp can jump to 103+ and stay there for days. Even at a wet bulb temperature above 110, it's going to take time for your internal temperature to heat up to that level. There's nothing "potentially in minutes" about it for humans that are used to the heat.
Sure, you do eventually have to get somewhere cooler. But a wet bulb temperature of 105F is not going to be fatal for a well adapted human even after a few hours.
Those do NOT occur regularly in the US at the same time (because the humidity peaks in the morning, but the temperature in the afternoon). Maybe in a few decades though.
35°C at 100% humidity is about the human survivability limit (at 6h exposure). This makes a lot of sense because humans generate ~100W of heat, but require their core temperature to stay constant-- if the environment is too hot and evaporation ineffective because of humidity, then your thermoregulation just breaks down and you die, just like from high fever.
Nope. A human that is regularly exposed to such environments has probably developed a strong cutaneous vasodilation response and can tolerate limited exposure just fine. Instead of a cold plunge in a frozen pond, they're doing a sauna. Human bodies are amazingly adaptable.