Processor Temperature

I have a Pentium 4 1.7 GHz running in a Gigabyte GA-8IRXP mobo. I have the supplied fan on the processor, a fan extracting from the case near the processor, and another fan extracting from the top of the full tower.

Generally the monitoring feature shows the CPU temp around 41 degrees Celcius, but occasionally this rises to mid to high 50’s (during video rendering etc).

What is a safe operating temp range for the CPU?