Continuous core body temperature measurements are made during hypothermic operations, where the core body temperature of the patient is lowered to reduce swelling. Caregivers monitor the patient's core body temperature to prevent damage that can occur to the patient if the patient's core body temperature becomes too low. To accurately determine the core body temperature of the patient, a temperature monitoring system measures the temperature at or near the surface of the patient and through at least a portion of a thermal block at multiple locations.