Abstract: Efficient downhole cooling of the electric pump motor, motor protector, and thrust bearing of a submergible pump assembly in a high temperature environment is accomplished without significant modification of the pump assembly itself. Coolant flows through an insulated shroud as a high velocity annular fluid sheet surrounding the components to be cooled. In a closed loop system, coolant from a heat exchanger is supplied to the shroud via insulated supply tubing, which contains a cable for energizing the motor, is injected into the shroud by a coolant discharge head from which the pump assembly is suspended, and returns to the heat exchanger via insulated return tubing. The walls of the shroud and tubing include expansion element which accommodate the difference between interior and exterior temperatures.