I am BAD with heat and when I was in a hot climate, I'd put ice in my camelbak. It helped lots by keeping my back cool

I'm the same way though, heat and I do not get along and on hills it seems like there is no cooling breeze. Probably due to the fact I'm not going that fast! It always seems like there isn't shade on hills either.

I don't know if drinking cold water is good for you (I am thinking not) but at the very least it would be nice to dump over your head!