A lighting fixture has an extruded aluminum housing, at least one light source mechanically supported by the extruded aluminum housing, and at least one copper pipe thermally coupled to the extruded aluminum housing to carry a fluid coolant. During operation of the lighting fixture, the fluid coolant flowing through the at least one copper pipe extracts heat generated by the lighting fixture, and the fluid coolant does not contact the extruded aluminum housing. In one example, a copper fluid coolant circuit is thermally coupled to the housing to contain the fluid coolant, and the lighting fixture does not contain any internal seals or internal O-rings for the fluid coolant.