 We have been overcooling buildings, which is wasting a lot of energy and making us all uncomfortable. Gail Brager is a professor at UC Berkeley. She studies something called thermal delight. It's that feeling when you step into a hot bath or put your hands around a warm cup of tea on a cold day. Brager says our bodies crave variety, and sitting in a sealed room for hours under a river of cold air is the opposite of delightful.