>>508732571 (OP)I have lived in the same American city my entire life in North Carolina. Summer has never changed, it has always been oppressively fucking hot. That said, if you size your AC unit appropriately and keep your car in your air conditioned garage you could live in a city where it was 130f for all i care. I never go outside anyway, and if I do it's in my air conditioned car. I'm not gonna collapse from 5 minutes in 130f.
Basically because AC, i'd say 130-140f is the max possible, but it would require special more insulated houses. Cars laugh at these temperatures as their operating ideal temperature is already closer to 200f and water coolant and radiators go brrr.
Anyways it was 100f here today at 95% humidity, and it will be like this all week. It's practice for hell. But I basically never go outside, so it doesn't really affect me.