Apparatus to control a temperature of a device that includes: a thermal head adapted to be thermally contacted to the device; a combined path to the thermal head; a first path maintained at a first temperature and connected to the combined path; a second path maintained at a second temperature different from the first temperature and connected to the combined path; a third path connected to the combined path; a pump assembly operable to circulate thermal transfer fluid: from the thermal head, through each of the first, second and third paths, from each of the first, second and third paths, through the combined path, and from the combined path, to and through the thermal head; and a valve assembly operable to control amounts of thermal transfer fluid that flow into the first and second paths, thereby controlling the temperature.