Stupid question... At what temperature can I let my processor reach before I start getting worried? I have an asus p4c800-e deluxe with a P4C 2.8GHz and under normal conditions it runs at 100F and at peak load (like rendering videos) 140F... I like to try to keep it around 100-110F, but if it jumps up like that is that okay?
I have the same CPU in an Abit board, and yes...it'll get that high on air. I, personally, put a limit of 175F/80C being too high for the core temp in P4's. I've placed that as my own threshold from seeing others letting the smoke out at around 180, and my own (mis)adventures and blowing a 2.6 at 183F. 175 gives me a boundry layer, if you will, to give me or my software enough time to notice and shutdown.
That can work as a general rule of thumb for damage to the CPU, but you can begin to "worry" far before that if you want. If it gets to 140F and levels off, then I wouldn't worry about damage, but I would take that a gesture to figure out something else to cool that puppy off. Everyone needs an excuse to tinker...if YOU need one, then this is a good one. I'd see what you can do to get that thing to idle at 90-95F (35C is a happy place to rest) and then see where it peaks at.
The reason you may be seeing it jump like this is that P4's ratchet down when they aren't being used. Then, when you wake it up, it starts to go to town on the temps. Your BIOS may have a setting for duty cycles. You may want to lower the percent if you aren't happy with the idle temps.