A thermal control unit supplies temperature controlled fluid to one or more thermal pads used to control the temperature of a patient. The thermal control unit includes a fluid outlet, fluid inlet, heat exchanger, pump, and a controller. The controller receives first and second data from at least two different sources to determine if the patient is shivering or not. The two different sources may include a temperature sensor adapted to detect a temperature of the fluid, a temperature sensor adapted to detect a temperature of the patient, a tissue oxygenation sensor, a vibration/motion sensor, a thermal image sensor, an electromyograph, and/or other sensors. In some embodiments, the thermal control unit takes one or more automatic actions in response to detection of patient shivering.
