I have wondered about this as well. I exercise a few hours before I plan on going to bed, and when I just get back, I'm very warm (as expected). Then, I drink about 40 ounces of water and consume a little bit of protein, and within a half an hour or so, I'm FREEZING. Still got plenty of layers of fat, so that's not the answer in my case, but it's pretty consistent and has been for years. But usually when I am exercising heavily, I am calorie restricting as well, so maybe it's just what sontaikle mentioned. I don't know the answer -- just my experience.
Biggest Loser Challenge - 12/29 - 03/16
Trainer boy challenge #3 (11/11-12/11):
Not successful. =(
(Trainer boy challenge #1 completed 09/11 - down 23.2 pounds - starting weight 239.8) (Trainer boy challenge #2 completed 11/11 - down 23.4 pounds - starting weight 216.6)