Yes, it does burn calories to both warm or cool food in your body, but it isn't really enough to do much. We learned in a science class once that it was something like 1 calorie for each change in degree for a liter of water. (That might not be totally right...I can't remember exactly.) Anyway, the point is that it isn't a lot. Drinking one regular glass of cold water is going to burn about 5 calories at the most. You probably burn more calories just walking to the sink to get the water. Don't try eating cold or hot food as a substitute for exercise...
