Thanks - I think that reading was a bit faulty it's showing 66C now.
I'd only just booted it at that point. This is an AMD3000+. Haven't overclocked it. Wasn't running anything CPU intensive at the time.
Haven't played HL2 in a while, got stuck at some bit I can't remember where! Obviously too hot to continue now!
ps As a general 'rule of thumb', what temp should you not exceed?
coolerxp - is that a software application I can download?
Thanks for your response