An apparatus for adjusting the body temperature of a patient comprises an enclosure defining an interior space for receiving at least a portion of a patient's body therein. The enclosure is adapted for substantially sealingly enclosing the portion of the patient's body within the interior space with the enclosure. Heat transfer liquid may then be circulated through the interior space of the enclosure via an inlet and an outlet for flow over the patient's body in direct liquid contact therewith to promote heat transfer between the patient's body and said heat transfer liquid. The heat transfer liquid may be either warmer or cooler than the patient's body temperature, to either warm or cool the portion. Controlled cooling may be employed to induce therapeutic hypothermia, while controlled warming may be employed to counteract unintended hypothermia. The apparatus further comprises a portable control unit that includes a liquid delivery system, a power source, a control system and a user interface for powering and controlling the liquid delivery system.