Sauna belts do work. Wearing a sauna belt during exercise is an effective method of reducing water weight. However, sauna belts are not designed to provide significant weight loss.
A sauna belt is a cordless band of fabric that is similar to a heating pad. Sauna belts are most often worn around the stomach to reduce bloating and to maximize the effects of exercise. When a sauna belt is turned on, the belt releases heat. Heating the body promotes excessive perspiration, which reduces the amount of water in the body. When excess water is eliminated from the body, a small amount of weight loss occurs.