A circuit card enclosure comprises a backplane including a plurality of connectors. First and second conduction rails are thermally coupled to a heat exchanger, the first and second conduction rails each comprising an inner body at least partially encapsulated by an outer body. The inner body comprises a thermally conductive material. The outer body comprises a structural material. Card slots of the circuit card enclosure are defined between opposed card channels of the first and second conduction rails. Each card slot is constructed and arranged to register an inserted circuit card with at least one of the connectors, the card channels including a thermally conductive region constructed and arranged to thermally interface with a thermal frame of an inserted circuit card, the thermally conductive region of the card channels being thermally coupled to the inner body of the conduction rail.