Still in my mid 50's, I believe that I am reasonably temperature tolerant.
I avoid Air Conditioning as much as possible. I have for years. I believe it is harder on the body to work outside in hot weather, then run into an ice chest.
Most of the temperatures around here top out in the mid 90's, although I have tried a few bike rides in 100°+ weather.
I also tend to let my house get a little cooler than average in the winter, with the opposite effect.