A headlamp assembly for a motor vehicle. The headlamp assembly includes a lens and a housing cooperating to at least partially define an inner chamber that is generally fluidly isolated from the atmosphere. Mounted within the inner chamber is a one piece reflector having a reflective portion and a heat sink portion. The reflective portion reflects light from a light source forward through the lens, while the heat sink portion conducts heat from the reflective portion and dissipates the heat from the assembly.