I don't know if I should ask this question on skeptics.se first, but I guess I'll try here first:
When I was a kid in summer camp, they served hot soup every day during lunch, even during a heat wave, with temps in the 100s. The head counselor would announce "Hot soup on a hot day keeps you cool". Was he just trying to get us to eat or is it true? And, my main question is, how does it work?