We just pack and go north, is our answer to adjusting to heat. We also had a Chiller
added to the pool to enjoy during summer. Not a fan of temp over 70, to say you get used to extreme heat, as you age one can have less mass, less muscle, cold is a norm. So maybe that’s how one acclimated to southern heat.
Doesn’t matter where you live elderly are cold in their house, car. Pretty sure our parents keep their heat on year round. 80-84 is their inside temp, and still wear a sweater. It’s hard to spend 5 minutes in their house.