Depends on the load to be honest. Some things do push the temperature up to 100, but it does depend on the task.
What I have noticed - mentioned on the 30-odd page thread on this forum - is that I've witnessed temperature spikes that appear and disappear in a matter of seconds. I can't expalain what is causing the effect, but Ive been able to trigger the effect at will in one partcular scenario. It's very odd.......but does it suggest that drivers may be partially responsible?