A cooling rack (10) for a plurality of electronic units (14). The cooling rack is primarily embodied by a mounting device (12) that removably docks the electronic units (14) so that a single, common cooling plate (20) is in thermal contact with multiple electronic units to simultaneously dissipate heat from electronic components within each unit. An ECU is also described which comprises internal thermal bridges (24) between with components therein and an interface surface, e.g. a rear wall, that thermally contacts the cooling plate.