As someone who grew up with AC, I was one time in Brazil and got stuck in a place without AC. Needless to say the first few nights was hell. I just couldn't follow asleep. However after few days, my body just adjust to the local temperature, and really enjoyed it. In fact, going into mall with AC just feels too cold for me then. Of course there is a limit to what our body can endure, but there is something to be said about exposing and adapting our body to the natural elements instead of just adjusting the environment to make what is comfortable to our body.

There's certainly a level of acclimation but if it were truly as enjoyable people wouldn't bother with cooling/heating buildings except in the most hostile environments.