Another thing you might try is eating soy products... I have a tendency to be cold (not excessively) but besides exercise the strangest thing is that when I eat beancurd (tofu) I can literally feel the heat radiating from my body even in a cold place... I don't feel HOT, just comfortable, but it is like the cold environment can't "touch" me. Perhaps this is some negative reaction from my body but in any case, it warms me up. Worth a try, at least!