An electrical connector assembly includes a connector housing and a busbar having a rectangular cross section defining two opposed major surfaces and two opposed minor surfaces disposed within the connector housing. A planar surface is defined by one of the two opposed major surfaces of the busbar. The electrical connector assembly further includes a cooling plate that is sized, shaped, and arranged to be in conductive thermal contact with the planar surface of the busbar. The cooling plate is configured to reduce a temperature of the busbar.