Therma-Kool Reusable Hot Cold Gel Pack is designed to provide comfortable pain relief when cold or hot therapy is required. Easy to Use: Freeze for Cold Therapy, Microwave for Hot Therapy. Remains flexible when frozen. Use Cold for effective first aid and therapy for sprains, headaches, migraines, TMJ, bruises, minor bleeding, blisters, burns & more. Use Hot for effective therapy and relief of body aches, sore muscles, stiff joints, sinus pressure, cramps, aches, pains & more. Proudly Manufactured in the U.S.A. Therma-Kool is a reusable gel pack designed to provide comfortable pain relief when cold or hot therapy is required. Therma-Kool remains flexible when frozen and is safe for microwavable use. Use cold for the treatment of sprains, strains, headaches, contusions, bruises, minor bleeding/burns. Use hot for temporary relief of muscle stiffness, aches and pains.