The Medium Sectional heating pack is designed to eliminate pain and swelling from larger parts of the body. The medium is great for the back, hips and larger areas. The heating pack is 100% natural and safe. Warm it up in the microwave or freeze it in the freezer.Our Bio-Engineers and Doctors worked closely with milling experts using a unique patented process, which removes the embryo/germ tip cap and outer coat from each kernel of corn. This leaves the purest and cleanest portion of the corn product. This process hardens the specialized de-germinated corn, allowing it to hold temperatures evenly for long periods of time. It also eliminates mold, fungi and foul odors often associated with natural heating/cooling products.Uses for Thermal-Aid Treatment Packs include: Arthritis, back pain, muscle soreness, menstrual cramps, neck pain, carpal tunnel, headaches, and migraines, sprains/strains, sunburn, fever, stomach aches and flu symptoms, bug bites, lactation, babies with colic (under adult supervision), multiple sclerosis and growing pains. See enclosed instructions for details.