Unfortunately, I too have been there, done that, and had the expired hardware to prove it.
I'm a bit paranoid now. My current desktop system is a quad-core Phenom 9850 on an Asus M4N78 Pro motherboard. I was doing some experimenting and needed to see the temperatures (which were not being displayed). I pulled up the Nvidia tool, and noticed that the onboard GPU was hitting 100 degrees C.
I had a small fan, so wired it to the heat-sink. That brought it down to the high 70s. Then I went online and found a Logisys High Performance Dual Heat Pipes Heatsink for Popular Mainstream North Bridge, Model: C8 (also has Deep Cool Chipset Cooler on the label). With that, the temperature is now hovering around 56 degrees C. That is much better. Fortunately, I caught it before it cooked the chip. I had to send this motherboard out for repair once already when the same issue did cook the chip. I was glad that it was still under warranty.
Anyway, all is now well. I have had the same misfortune with some of my other hardware in prior years. The worst I ever saw was when I was in the Army, stationed in Berlin, Germany. I saw a monitor go up in smoke. Boy did that ever stink up the place! At least that one was not mine.