I've never had a problem with overheating (even now) as the stand my PS3 was on is open ended.
Had the problem on Saturday whereby the PS3 shut itself down twice, but after that it went back to normal. In fact I played on Burnout for an hour on Sunday with no problems at all!!!
I was under the impression that once you got YLOD that was that, but I've been managing to get it on for 2 minutes at a time. With any luck I'll be able to boot it up long enough to transfer game saves/data.