A european friend told me about a water diet. Apparently you can lose weight by drinking a lot of cold water and then immediately jumping into a hot jacuzzi. The theory is that your body will spend a lot of energy to bring the cold water up to body temperature. Eventually you need to get out an pee away the (now)-warmed water and you do it all over again.
It sounds like it could work, but I have better things to do in my life than spend it laying around a jacuzzi. Don't I?