Instant Hot/Cold Packs are made from flexible material that is designed to conform to body contours for on-the-spot, convenient use. Instant Cold Packs are activated with a single squeeze to offer immediate relief to injured areas and help reduce swelling. The packs are ideal for minor sprains, burns, nosebleeds and headaches. Instant Hot Packs provide soothing warmth and are perfect for neck pain, arthritis, back and shoulder injuries muscle strains, aches, tension and cramps.