I wouldn't worry about it. If you have a decent CPU cooler, just let it do its job - if it's too hot, it will throttle or shut down. I have also yet to find a CPU (Pentium 2, 3, 4, Athlon XP, Pentium M, Core duo, Core 2) that cannot withstand temperatures of at least 80 degrees.
I run an AMD powered server in my loft and it is often 35 degrees in there in the summer - fans make a racket (can't be heard outside of the loft though!) but it continues to work just fine. No idea of CPU temps.
