Jeff-o, at 300 ma. without a heat sink the Emitters became too hot to touch after 10 seconds or so, but it takes only a small heat sink to keep them happy. The problem is all the heat is produced in such a small area. A properly designed flashlight will have some way of keeping the LED cool. I wouldn't expect the body of the flashlight to get very hot even with a 3W Emitter. You will get plenty of light though!