I've heard that about ice water, but not about the ice packs. Interesting. In my anthropology courses, we talked about indigenous groups and the different body types/diets depending on the climate. While people in colder climates generally tend to be able to eat much higher calorie diets, they also tend to be a bit...stout. This, of course, is talking more about people who don't necessarily have the conveniences of heating and cooling systems where they live, and in general tend to have a moderate to high activity level.
So I guess what I'm saying is... it's possible.