Well... that's a Prescott and they can get up to 70 C under full load. Above that they begin to throttle to cool themselves down, so you really can't hurt the chip from a safety standpoint as long as you aren't turning up the voltage. There is a utility called "Throttlewatch" you can download which will tell you if your chip is throttling.
The newer Prescott's seem to run a little cooler, but as you clock them up higher, it's a hockey stick in terms of thermal problems.
Scout
700 Mflops in SETI!