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Heating pad

Heating packs of various types have long been used in the medical field and by sportsmen for the purpose of applying heat to localized areas of the body to alleviate stiffness or minimize tissue damage due to freezing, for example. The value of heat treatment for easing and preventing the onset of pain in muscle tissues is well established. For example, muscles which tend to cramp may be heated before strenuous exercise to enrich the blood supply to the appropriate areas. Means for effecting such heat treatment include the use of electrical heating pads. A therapeutic heating pad which is made of a phase change or thermal energy storage material typically includes an envelope filled with a phase change material. The phase change material is in a solid or gel-like format normal or room temperature. When the heating pad is to be used, it is put into water and heated so that the phase change material absorbs heat and is transformed into liquid, thus storing thermal energy. At this time, the heating pad can supply heat for therapeutic purposes. Electric heating pads are generally characterized by the fact that they are flexible and therefore can be adapted to parts of the body that need to be heated. Heating pad temperature control may be achieved by controlling the amount of power delivered to the heating element within the heating pad. The amount of power is in turn controlled by altering either the amount of continuous power applied to the heating element, or intermittently applying power to thereby alter the amount of time during which power is applied to the heating element.

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