Heat and cold therapy are great, natural ways to relieve pain. Heat therapy, also known as thermotherapy, can help increase blood flow in painful areas and relax sore and stiff muscles for pain relief. Cold therapy reduces inflammation and swelling, especially after exercise. The Thermal-Aid Medium Sectional Pack is designed to be a 100% natural way to comfort and soothe bumps, bruises, and sore spots. Each pack contains a heating/cooling element composed of specially engineered corn. The 100% natural cotton is washable and reusable. Ideal for treating arthritis, sports injuries, sprains, and strains, the Thermal-Aid Medium Sectional Pack will provide pain relief in minutes! Simply place the heating/cooling pack in the freezer or heat in the microwave for the perfect problem solver. They are great to help reduce fevers when applied cold out of the freezer and they also are a great heat source for bed time. Thermal-Aid products, manufactured by Pacific Shore Holdings Inc., is a revolutionary, 100% natural therapeutic heating/cooling treatment pack specifically designed for the medical field, to reduce swelling and relieve pain. After two years of research and development, and working with medical professionals regarding the benefits of direct and prolonged heating and cooling to both humans and animals, the prototypes were created and the concept of ?Thermal Aid? was born. ? 100% natural pain relief in minutes ? Soothes sore muscles, aches, and pains ? Cold therapy for sprains and other injuries ? Heat therapy for ongoing aches and pains ? Medium size is great for back, hips, and shoulders