The Veridian Gel Sleeve's revolutionary design surrounds the treatment area and delivers soothing comfort and compression. It can be used for cold or hot therapy. Cold therapy reduces the extent of swelling and bruising, and provides pain relief caused from acute injury, strains and sprains—just store in the refrigerator or freezer for instant use. Hot therapy provides pain relief to sore or stiff muscles and joints, relaxes muscles and increases blood flow to the treatment site. Just use hot water to prepare.