An enclosure with hybrid thermal management for a heat-generating electronic device comprises a passive heat sink for conducting heat away from the electronic device, a cold skin adapted to slide over the top of the passive heat sink and having a front wall forming a plurality of air intake ports, and a plurality of blowers mounted inside the cold skin for drawing air into the cold skin though the air intake ports and then directing the air through the passive heat sink. In one implementation, the passive heat exchanger includes multiple thermally conductive fins adjacent to the electronic device and extending rearwardly from the intake ports, the fins being spaced apart from each other for conducting heat away from the electronic device. The blowers preferably direct air rearwardly from the intake ports in the front wall into the spaces between the thermally conductive fins.