A piston assembly for a compressor that reduces the temperature experienced by a compressor cup seal during operation of the compressor. The piston assembly includes a piston sleeve having a top portion and an interior. A valve plate is supported by the top of the piston sleeve. A compressor head includes a compressor head plate, which is offset from the valve plate. The offset between the compressor head plate and the valve plate defines a cooling chamber. The interior of the piston sleeve communicates with the interior of the compressor head via openings defined in the valve plate and the compressor head plate and conduit associated with these opening and traversing the cooling chamber.