I overclock my system a fair amount(Barton 2500 running at 2.3GHz).  Processor temp is never more than 13 degrees above ambient, and I also have 7 cans of air duster in the corner of my room ready to go <grin>  It's amazing the state of some of the pc's I have to fix for other people though.  Some of the stuff I've seen inside pc's is crazy (including (but not limited to) spiders nests, coins, a credit card, the list goes on ) .....