The Insta Heat Reusable Hand Warmers provide therapeutic heat therapy where you need it most. Pinch the small metal activator floating in the bag so it snaps. This trigger will start a unique, instant crystallization process that produces heat up to 130 degrees Fahrenheit within seconds. The packs will actually change from liquid to solid, conforming to your body, emitting heat through the physical change. These heat packs can produce therapeutic heat for up to two hours or more. Heat times are extended by using any form of insulation. Once the heat pack is discharged, just simply recharge it by placing it in boiling water for several minutes and following the instructions printed on each pack. Insta Heat Hand Warmers are also portable, so they can be used at home or office, while driving or commuting, or while attending or playing sports. Stop living in pain and discomfort and purchase the Insta Heat instant and reusable heat pack today!