A cooling system for an indwelling heat exchange catheter (12) includes a heat exchange bath (14) that is configured to receive a conduit (17) that carries saline to and from the catheter (12). A heating/cooling fluid is in the bath (14) and exchanges heat with the saline. The heating/cooling fluid flows through a heat exchanger (40) that includes a refrigerant and a variable speed DC compressor (62) for removing heat from the refrigerant. A coolant pump (46) circulates the heating/cooling fluid between the heat exchanger (40) and the heat exchange bath (14).