Relief Pak® Cold and Hot Donut® Compression Sleeve compress gives heat therapy, cold therapy also compression. The roll-on pack is easy to apply and stays in place without straps. The pack provides cold or hot treatment to soothe discomfort from arthritis, sprains, strains, bruises and swelling. Simply heat the pack in microwave to make it warm, or chill in freezer to make cool. Every pack comes with a compression sleeve to wear between the pack and your skin.