A fluid heat exchanger unit cools an electronic device with a cooling fluid supplied to an upper portion of a cooling housing. A refrigerant is disposed in a lower portion of the cooling housing for liquid-to-vapor transformation. A partition divides the upper portion of the cooling housing from the lower portion. A heat rejecter is disposed on and above the upper wall of the cooling housing with a first header extending from and in fluid communication with the liquid coolant outlet. A second header extends upwardly from a rejecter outlet. A plurality of first tubes extend between and in fluid communication with the first header and the second header with a plurality of first air fins disposed between the upper wall and the first tubes. A single unit defines both the cooling housing and the air cooled heat rejecter to thereby allow the manufacture of the unit in a single process with the attendant reduction in shipping, handling and installation.