I checked the head several times and in several places. (Don't know if I've checked per say the base of the head though) I thought is was to cool also, but I've used this same infered gun to check electric motors that were over 200, and the DA is no where near that hot. Not lean on vertical runs at all. Can be TR'ing for a minute or so, go to full throttle till I can't see it anymore and it never sags.