 This is a hot or cold gel pack that can be used for any injuries to help reduce inflammation, pain or discomfort to any injured area. To use it as a hot pack, you can place it in boiling water either from the microwave or the stove top. Leave it in for about 5 minutes. For a cold pack, you'll want to leave it in the freezer for about a half hour. Before you place the pack to an injured site, you first want to cover the area with the cloth. Then you'll place the pack directly over that cloth to the area that you're trying to reduce the swelling.