USE INSTRUCTIONS: Store it in the refrigerator for bout 2 hours or more until arriving at a satisfying temperature. FUNCTIONS: These cold packs are used to reduce inflammation and swelling by lowering skin temperature. Additionally, they are used to help relieve pain by numbing injured tissues and reducing muscle spasms. This product is ideal for sprains, strains, contusions, minor burns, toothaches, simple headaches, insect bites and many first aid needs.