Hot water therapy aqua-relief system is an automatic hot cold therapy system that delivers instant heat through patented wraps that go around your feet and hands to provide greater circulation and to reduce pain. Hot therapy is generally used for chronic injuries or injuries that have no inflammation. Sore, stiff, nagging muscle or joint pain is ideal for the use of heat therapy. Athletes with chronic pain or injuries may use heat therapy before exercise to increase the elasticity of joint connective tissues and to stimulate blood flow. Heat can also help relax tight or spasm muscles.