A processing system utilizing a supercritical fluid for treating a substrate is described as having a pump for recirculating the supercritical fluid over the substrate. For various applications in supercritical fluid processing, the fluid temperature for the treatment process can elevate above the temperature acceptable for safe operation of the pump. Therefore, in accordance with one embodiment, a fraction of supercritical fluid from the primary recirculating flow of supercritical fluid over the substrate is circulated from the pressure side of the pump, through a heat exchanger to lower the temperature of the supercritical fluid, through the pump, and it is returned to the primary flow on the suction side of the pump. In accordance with yet another embodiment, supercritical fluid is circulated through the pump from an independent source to vent.