A lighting apparatus for use as a surgical headlamp is disclosed. A light emitting diode is positioned in a recess within a frustoconical, thermally-conductive heat sink that has a several circumferential ridges to provide a desired surface area for heat transfer. The diode and the heat sink are provided in a housing that also includes a fan for drawing ambient air into the housing to contact the heat sink and exhausting heated air. A lens is snap-fit into a slide that frictionally engages the interior of the housing, allowing a user to adjust the spacing between the light emitting diode and the lens as desired. Personal cooling apparatuses usable with the lighting apparatus are also described. Auxiliary undergown switches are also described as are personal cooling apparatuses.
