Products that will keep my PS3 cool?

My PS3 has been awesome since I bought it in '08 (despite the PSN getting hacked, lol). But today I was playing online and the fan kicked on after about 2.5 hrs of play. "WTF is that noise", I thought to myself. I figured I should stand it upright and drag it off of my entertainment center. So after letting it cool I played it with it out on the floor and upright - it didn't come on, but I didn't play for that long either. I pushed in into the corner (beside entertainment center) and it is still upright, I played another match and it came on. Are there ANY products worth buying that will keep it cool? If I continue playing is the fan a BIG concern or is it just doing it's job?