I don't know how to teach that - it just don't bother me. I have several people tell me when it comes to handling the heat that I am tougher than fried coyote.
Heat or (most) cold don't bother me. I can take 100+ easily, all day long. For the cold, I don't like just being in it, but if I am out doing something (hunting or fishing generally) it is not a big deal.