[imported_Sindern]

Most modern computers have a thermometer that keeps track of the processor temps and if it gets to a dangerous level, then the computer will power off. No shutting down, no warning, just POOF it's off. I had a problem like that with an AMD processor (every one I've ever had has been ridiculously hot) and I ended up just taking the case off of the computer and putting a box fan on it. Janky as hell but it worked.

Also, a lot of the newer processors will pump out a lot of heat and they usually ship with a crappy heat sink. If you're having problems, you might invest in a new heatsink and some good thermal putty. I like Arctic Silver for a thermal paste, and my current heatsink is a Zalman. It looks wierd, but it's freaking amazing.