A burn-in testing cooling system includes a heat pipe having a tubular body. A capillary wick is disposed on an evaporator portion of the tubular body, and a base seals off the evaporator portion. The base is sized and shaped so as to be releasably thermally engaged with a semiconductor device during burn-in testing. A working fluid is disposed within the heat pipe in sufficient quantity to at least saturate the wick. A hollow tube is coiled around the exterior surface of the heat pipe such that a first set of interior coils are formed adjacent to the exterior surface. These interior coils are brazed to the exterior surface so as to enhance their thermal interface with the heat pipe. A second set of coils are wrapped around the first set of coils, in overlying relation to them. A source of coolant is arranged in flow communication with a second open end of the coiled tube, and a pump is arranged in flow communication with the source of coolant and a first open end of the coiled tube so as to circulate the coolant through the first set of interior coils and the second set of coils.