This gel bead technology is able to offer both cold and heat treatment. Freeze or microwave the packs depending on your needs. Features an integrated soft material support for dual temperature usage. Applies your choice of heat or cold to sore muscles, aches or pain. Great for use on almost any body part, including shoulder, upper/ lower back, knee, elbow, cervical, wrist, rotator cuff, head, eye, perineal, ankle and foot. Great gift for health events.