Most computers Are set to shut off at 60 degrees celsius. You should have 1 or 2 good fans as an exhaust and maybe 1 or 2 fans on the front or side of the case as an input for cooler air from outside. Also a good idea is to have a very good fan on the chip as the newer chips run hotter than older ones. I have 6 fans on my 2.8 Ghz p4 and it still runs at 34-36 degrees celsius. If you enter the bios on your comp you can see the temp of it. It is also proven that your RAM and Chip work faster and better the cooler it is.