Soothing Heat, Relieve Pain. Thermophore Classic Deep-Heat Therapy Pack is designed with a special hand-held Easy-Comfort switch. Just press for heat, release to cool and alternate as often as you like. If you happen to doze off and your hand relaxes, the unit will cool as a safety feature. Professional-quality intense moist heat can also be used at home for therapy any time of the day or night. Thermophore is the brand most often used and recommended by doctors, physical therapists, and other medical professionals. Unique design produces moisture from the atmosphere, with no need for you to add any water. If needed, Classic Plus and MaxHEAT Plus styles have a protective liner that lets you safely add a damp cloth for even more moisture