I try to clean all my tools after I use them by brushing them off and follow that with a couple of blast of compressed air to get rid of as much dust build-up as I can, I also use the vac on the unit where I see dust building-up when I change grits, plus I vac off the fave of the pad and both sides of the sand paper. A little OCD I know, but the stuff cost a bunch and alot of my tools are over 30 years old (none of those are Festool sorry to say) and I am a professional user. I also did not read that you were or were not hooked up to some sort of DC or vac? My RO 90 does heat up a little bit, but not to an uncomfortable temp.,but I live in FL. and I'm old w/nerve damage to my hands so it might be hotter than I think. the only other thought I would have would be you method of holding the tool, for most of the sanding I hold the head ( area above the pad ) in one hand and the plug-it cord and hose in the other lightly. For one handed work, I hold the barrel ( upper part of the tool in between the head and the plug-it ) of the tool firmly. You may be just covering the vent ports of the tool making it over heat and try taking a breack every now and then, [smile]B