Thermal treatment garment and method of thermally treating body portions

A thermal treatment garment of the present invention includes an outer structure layer, an interior lining formed of a gel material that directly contacts a body portion of a user when the garment is worn by the user and a thermal treatment layer to thermally treat and control temperature of the garment. The thermal treatment layer heats and/or cools the gel material to a selected temperature or selected temperature range and is controlled by a controller. In an exemplary embodiment, the garment includes a cap to thermally treat the user's head, where the structure layer has a generally convex outer surface and the interior surface of the gel layer is generally concave and contoured to engage with and at least partially envelop at least one selected portion of the user's head.