Hottles are a portable and convenient way to enjoy the benefits of thermal heat therapy. The unique, patented Hottle thermal heat pack contains no flammable gels, grains, or materials. Simply microwave the hottle as directed and the thermal pack will stay warm for up to four hours, providing radiant, gentle, constant heat. Use it for relief from aches and pains, to warm up during colder months, or to soothe and comfort children.