[PLMUV9A4UP27D]

It's a good point about living in a hot climate often being associated with living a happy life. Although to what I've seen, there isn't much evidence for such a correlation.

[BurningFrog]

Simple theory:

In a warm climate you see people walking around feeling comfortable.

In a cold climate, the people you see are freezing.

[bluGill]

People are not freezing in a cold climate - they have plenty of coats on. In hot climates you run out of clothes to take off - even nudists.