An apparatus for rapidly cooling or heating the body temperature of a patient comprises:a pump portion for withdrawing blood through a blood inlet and returning blood through a blood outlet；a heat exchanger portion for selectively heating or cooling the blood； anda blood conduit between the blood inlet and the blood outlet of the pump portion, the blood conduit being in direct thermal contact with the heat exchanger portion to selectively heat or cool the blood,wherein the heat exchanger portion comprises:one or more thermoelectric modules contained between a pair of ceramic substrates； anda heat sink in thermal contact with the one or more thermoelectric modules for removing heat from the one or more thermoelectric modules.
