A lighting system for an automotive vehicle has a housing adapted for mounting to the vehicle with a generally outward facing backplate and at least one socket for an incandescent light source. A transparent lens cover is attached to the housing and forms an internal chamber between the lens cover and the housing. A staircase circulator on the housing comprises a plurality of steps and risers rising from the backplate toward the lens cover along a path that is spaced from the socket, wherein the path is generally along a natural convection flowpath of air within the chamber.