In clutch or brake cooling, a conductive brush (104) is arranged between a plate (102) and a separate cooled component (106), in order to reduce the temperature of the plate. The applied pressure from said conductive element may be responsive to the temperature of the plate. For example, the brush may be operable to move to an active, rubbing position from a non-rubbing position under predetermined temperature conditions. Similar brushes can be incorporated into bearing assemblies for clutches and brakes.