I wonder if it's physical or at least partially psychological.

I live in Los Angeles and my brother lives in Flagstaff. Every year at the holidays, I go spend a week with him and his family. In Flagstaff there can be entire days below freezing and the nights can easily reach single digits F. When I'm there and it's 25 F, I'm fine. Toodle along like normal. Come back to LA and it's 50 and I shiver. Same outfits even. It's the strangest thing.

Maybe altitude? FLG is 7000 ft and LAX is more or less sea level. I dunno.