Well, if mitochondria is uncoupled you produce a lot more heat and less ATP, so naturally you'd sweat a lot. High adrenaline can also make you sweat but it also makes your hands/feet cold, while uncoupling should make you hot all over. Uncoupling should always cause sweating, even with good metabolism, since the body needs to cool off somehow and sweating is the natural way to do it. I guess mild uncoupling is preferable unless you are trying to lose weight, since too much heat and not enough ATP can leave you exhausted. Just ask anybody who has used DNP for weight loss - they feel drained at the end.