I believe, though others with more experience than me will put me right, that the temperatures of the cpu cores really shouldnt be any where 100 deg C. Like, no where near, ever.
I am looking at my stock Q6600 idling at the moment with temps of 31,30,24,24 across the 4 cores. Even under load its not getting near 50.
Check that your heatsink and cpu fan are properly connected, that the fan is running, and that you have used some proper thermal interface compound (TIM) between the heatsink and the cpu, something like Arctic Silver thermal paste.