TECHNOLOGY FOCUS - ELECTRICAL POWER AND ENERGY - Preferred Component: The direct contact heat exchanger by-pass system comprises by-pass valve for directing the coolant to flow from the coolant loop through a by-pass feed line to the radiator and from the radiator through a by-pass return line back to the coolant loop by-passing the direct contact heat exchanger; water immiscible fluid isolation valve for restricting flow of the water immiscible fluid from the direct contact heat exchanger and radiator loop into the coolant loop, when the by-pas valve are directing flow of the coolant directly from the coolant loop to the radiator and back to the coolant loop by-passing the direct contact heat exchanger. The by-pass valve comprises a coolant loop by-pass feed valve for selectively directing flow of the coolant from the coolant loop into the by-pass feed line, a direct contact heat exchanger feed valve and direct contact heat exchanger by-pass valve (83) for selectively prohibiting flow of the coolant into the direct contact heat exchanger, and a radiator loop by-pass valve for selectively directing the coolant discharged out of the radiator into the by-pass return line. The water immiscible fluid isolation valve comprises a direct contact heat exchanger discharge valve secured in fluid communication with an outlet of the direct contact heat exchanger for selectively prohibiting flow of the coolant out of the heat exchanger, and a radiator inlet valve secured in fluid communication between the by-pass feed line, the direct contact heat exchanger and radiator for selectively directing flow from the by-pss feed line or the heat exchanger into the radiator.    TECHNOLOGY FOCUS - ORGANIC CHEMISTRY - Preferred Material: The water immiscible fluid is perfluorocarbons and/or hydrofluoroethers. It is alkanes, alkenes, and/or alkynes having greater than or equal to6C.    TECHNOLOGY FOCUS - POLYMERS - Preferred Material: The water immiscible fluid is silicones, silicone copolymers, substituted silicones, siloxanes, polysiloxanes, substituted siloxanes, and/or polysiloxanes.Preferred Property: The water immiscible fluid has a freezing temperature of less than or equal to-20degreesC, a surface tension of less than or equal to35, preferably less than or equal to20 dynes/cm, and a solubility in water of less than 0.1%.