Reusable cold and hot compress always stays flexible. These economical gel packs are non-toxic, microwavable and made with extra strong bags. For cold compress place in your freezer for 1 hour, then apply to the area you are treating over a dry towel. For hot compress, boil a pot of water, remove from heat and place compress pack into hot water for 5-10 minutes. For microwave use, place in a container and cover pack completely with water, heat at full power for 1 minute. Wrap pack in a towel or a fleece cover and apply to area you are treating. Available in three sizes.