Heating or cooling pad or glove with phase change material

A heating or cooling pad for reducing pain or swelling, or increasing range of motion, includes: (a) phase change material having a melting point of between about 42 and 65 degrees Centigrade, or between about −10 and 6 degrees Centigrade; (b) a gel or viscous fluid carrier in which the phase change material is relatively evenly distributed; and (c) a fluid-impermeable, conformable envelope surrounding the phase change material and the carrier. A preferred embodiment herein includes: (a) a fluid-impermeable, flexible, conformable envelope; (b) a mixture of from about 10 to about 75 weight % of alkanes having a carbon chain length of between 12 and 14 or 22 and 30, and from about 25 to about 90 weight % of a gel or viscous fluid carrier in which the alkanes are substantially evenly distributed, the mixture being sealed within the envelope; and (c) at least one layer of insulation adjacent to a first side of the envelope. The envelope is preferably sandwiched between comfortable, conformable layers of insulation.