Relief Pak Cold n' Hot Elastomer wraps and pads are supple enough to contour to the applied location. They can be chilled or heated to be used as a cold or hot pack. Non-toxic material maintains its flexibility even when below freezing. The elastomer wraps and pads provide a convenient way to position and apply cold or hot therapy. The tough, flexible gel, specially selected fabric and hook/loop straps provide an exceptionally durable product. The deluxe wrap allows cold or heat to reach the affected areas. They stretch cover allows conformity, heat transfer and comfort. These packs can be heated in the microwave but do not try to heat them in water.