Well, it depends. I realize hypothermia is a problem in a lot of places, but where I live, it hasn't been below freezing during the time I've been here (15 years), and I've never had air conditioning while I've lived here. (It gets hot enough a couple of times a year that I may go to a mall or store with A/C, but it's never been a consideration to get an air conditioner here).

I agree that shelter is a top priority, but I wouldn't rank it over water where I live - I could go a long time without a formal shelter, but I'd definitely need formal water. :->