For the Pentium(R) 4 processor, maximum temperature specifications will vary on the operating frequency and stepping of the processor. There is no average temperature; there are too many variables that affect the operation of the processor and the system. The processor should operate at peak performance while the maximum case and chassis temperatures are below the maximums. (Case temperature is the processor temperature reported by the thermal diode within the processor)
This link has the thermal specs and recommendations.
http://support.intel.com/support/pro...m4/thermal.htm