Nahh, I just run hot. I've lived in a shared place where I don't control the thermostat and the person who does was loathe to let it go above 77 degrees. After months on end, I'd still get uncomfortably warm in such a temperature. On the other hand, I can sit comfortably in 55 degrees in short sleeves with wind. I also have very low body fat, so that's not the culprit either. Believe it or not, people have different preferences and optimal temperatures. I just wish everyone would err far to the side of cold: you can always put on a jacket; I can't keep taking clothing off.