An ultrasound imaging system includes a thermally conductive frame and a number of electronic components and a display that are sealed within the frame. The frame further includes a plenum extending through the frame with surfaces that are thermally coupled to the electronic components and the display. An active cooling mechanism, such as one or more fans, moves air through the plenum to remove heat generated by the electronic components and display. The plenum is environmentally sealed so that moisture, dust, air or other contaminants drawn into the plenum do not contact the sealed electronic components and display in the frame.