Soft Comfort CorPaks Hot or Cold Therapy Packs are the perfect solution to help relieve headaches ease pain and help reduce inflammation associated with strains sprains and other soft tissue injuries. Conveniently store packs in the freezer for cold therapy the moment you need it! These packs stay soft and flexible comfortably contouring to painful areas. Use cold to help reduce inflammation; warm packs in the microwave to aid muscle relaxation and to promote healing. The pack s exterior is made of a blend of synthetic fibers and organic plant materials. The Soft Comfort CorPaks are filled with a greater amount of fill compared to traditional packs incorporating a proprietary blend of bentonite clay and food-grade propylene glycol; enhancing their ability to retain cold and heat for extended periods. The soft frost-free pack is gentle on the skin and does not need to be wrapped in a towel. For cold therapy place pack in the freezer for a minimum of 1 hour prior to use. For heat therapy simply heat the pack in a microwave according to the heating instructions printed on the pack. The pack will maintain therapeutic temperature for 20 minutes. When not in use the pack may be stored in the freezer for convenience. Do not sit on or place excess weight on pack. Reusable. Latex free. Made in USA.