Abstract: A temperature controller senses whether the temperature of a body (30) is higher or lower than a desired temperature, and then heats or cools the body (30) in either a high power mode or a low power mode. The controller operates in the low power mode if the elapsed time from the last change from heating to cooling or cooling to heating is less than a predetermined time interval. This condition typically occurs when the temperature of the body (30) is near the desired temperature, i.e., the controller is switching back and forth from heating to cooling in fairly short time intervals. If the elapsed time is longer than the predetermined time interval, as typically occurs when the temperature of the body (30) is being changed to a new desired temperature, the controller operates in the high power mode.