A few days ago I powered up my system as usual and I was loading up World of Warcraft while checking some emails and I took a random shutdown. Thinking power went out, I checked my clock and it was still on. I tried to power up but it wouldn't, so fearing the worst I unhooked everything, pulled the side panel out, and did some checks. I didn't smell anything burning, but I did touch the CPU heatsink and it was really hot. I waited a few minutes, powered back on, and ran into the BIOS to check my temps. To my shock, the CPU temp was hovering at 79C and dropping, and remembering I left I automatic shut down temp I put on at 80C for the summer. I left the bios and when I got into windows, I shut it down for an hour. I turned it back on, left Coretemp on and watched it through out the day and it never happened again (yet). When this happened, it was only 10am while it was still cool inside my room (say, maybe 60 F degrees). My question is, what could cause high temp spike just after powering up? My case does have good air flow and the what not. Think I should consider replacing the heatsink? My stats are in my signature, and I am using the stock intel heatsink.