Right at this moment I'm compressing a big file with winrar so my CPU is at 100% usage. and this program is telling me my CPU is 47-48ºC. I don't think that's safe... is it? P4 2.4a Northwood stock speed and HSF.
That's not too high for a processor under load. In fact that's about where my northwood is running right now. I have Intel's Active Monitor installed, and the intel presets are "Yellow" level at about 130 degrees fahrenheit, and +160 df for the "danger zone". If you're concerned you can always clean your case of dust, add more fans, and buy a bigger heat sink/fan, but from my experience 116 is fine; far from the trouble areas.
Thats cool compaird to a lot of systems...hell whne i was finding max OC i hit 68*c under load @ 4.3ghz..Intel has a built in thermal cut off..so if it gets to that point the chip will protect its self.