Apparatus and method for maintaining processing devices at a nominally common temperature, such as but not limited to storage devices in a multi-device networked storage enclosure. In accordance with some embodiments, an enclosed housing has a first side adjacent a cold zone with a lower ambient temperature and an opposing second side adjacent a warm zone with a higher ambient temperature. First and second processing devices are arranged within the enclosed housing so that the first processing device is adjacent the cold zone and the second processing device is adjacent the warm zone. First and second thermal interface material (TIM) modules are contactingly affixed to the first and second devices and are provided with different heat conductivities so that the first and second devices are maintained at a nominally common operational temperature.