What temperature range should my Mobile Intel Pentium 4 - M CPU 2.20GHz 512MB RAM be operating at.

It is in a Dell Inspiron 8500 notebook computer.

Is there a specifications page that you can point me to that will show this information?

It rather easily climbs to 70/72 degress Celsius, where the fans come on; especially while surfing FF with multiple tabs.

Fans bring it down to low 60s pretty quickly.

Have gotten temperature down to high 50s, but ONLY with 12 inch external fan blowing on it.

Got it used. Could it possibly be overclocked? How do I tell?

Those temperatures, even if you get them down into the 50-60* C range, are "excessive".

For a reference point, I opened an old Dell Inspiron 8500 (6 years old).
I then opened 4 instances of FireFox and one instance of IE which is presently logged onto Yahoo and displaying a Video feed of a popular TV program news item.

Using Everest 2.20 (free version) my temperatures are currently 39* C (CPU) and 44*C (hard drive)

The machine has been running for about 30minutes and has completed a few updates and background scans during that time, with the above browsers open and active.

I do not know of any "reference list" available anywhere, and have often wished there was one, but do not believe it would be of much real practical use when investigating any specific machine.

Comment: If hardware manufacturers committed to a table of expected temperatures and the table indicated an upper safe temperature, they'd probably start getting a lot of RMA returns of hardware that wasn't actually faulty.

You've got a HEAT problem.
Check your fans.
Check for dustbunnies, even if you've previously cleaned inside.
Look again carefully.

You've previously mentioned that your area's climate is hot right now.
Environmental heat will generally "contribute" to heat in a computer, but not to the extent of your current temperature readings.

How about your building's electrical system?
If you have poor/faulty wiring, your PSU may be working harder than necessary.

Have you made any physical changes inside of your machine?
Installed new hardware?
Removed and replaced the HeatSink of your CPU?

These kinds of problems need to be fixed, but can be difficult to diagnose.
Therefore as much information as you can provide could help.

Best Regards

39 C. That is exactly the temperature my machine dropped to, in the blink of an eye, once I closed the 4 firefox windows and 60 tabs I had open AND closed my wireless modem control software. I mean EXACTLY. Typically, I have been focused on the CPU temperature with everything running, but I am now watching everything so I noticed that huge temperature drop.

Correction. That is exactly the temperature it dropped to with a 12 inch external fan 2.5 inches away on high.

http://processorfinder.intel.com/details.aspx?sSpec=SL6VB

You do not have a heat problem. Mobile chips naturally run hotter than desktop chips, and as such are designed to run hotter.

as long as you're under 100 degrees Celsius, you're fine. Seeing load temps of 70-79 aren't unusual, but if it cracks the 80 barrier, that's when you should get a little worried. Use the manual ( http://docs.us.dell.com/support/edocs/syst...00/sm/index.htm ) to open your computer up and clean out the dust. You might also want to invest in some Arctic Silver 5 (aka AS5, available from any computer store worth it's weight in salt), clean off the thermal interface material (TIM, for short) between the heat sink and CPU (see the pics in the manual; both the CPU and the part of the heat sink in contact with the CPU should look clean and/or shiny. Use Q-Tips and Rubbing Alcohol to clean, and don't be afraid to use some elbow grease), and use a razor thin layer of AS5 to better transfer the heat from the CPU to your cooling solution.

Or pay someone to do the aforementioned steps.