An apparatus and method for metabolic cooling and insulation of a user in a cold environment. In its preferred embodiment the apparatus is a highly flexible
composite material having a flexible matrix containing a
phase change thermal
storage material. The apparatus can be made to heat or cool the body or to act as a thermal buffer to protect the wearer from changing environmental conditions. The apparatus may also include an external
thermal insulation layer and / or an internal
thermal control layer to regulate the rate of heat exchange between the composite and the
skin of the wearer. Other embodiments of the apparatus also provide 1) a path for
evaporation or direct absorption of
perspiration from the
skin of the wearer for improved comfort and
thermal control, 2) heat conductive pathways within the material for thermal
equalization, 3) surface treatments for improved absorption or rejection of heat by the material, and 4) means for quickly regenerating the thermal storage capacity for reuse of the material. Applications of the composite materials are also described which take
advantage of the composite's thermal characteristics. The examples described include a diver's wet suit, ski boot liners, thermal
socks, gloves and a face
mask for
cold weather activities, and a metabolic heating or cooling
blanket useful for treating
hypothermia or fever patients in a
medical setting and therapeutic heating or cooling orthopedic joint supports.