Recently I was given a Dell Latitude 1501 that was "Virus-ed to death". After reformatting the hard drive and reinstalling Windows there were other issues that I needed to fix. The mouse pad did not work because water had been spilled into it and the computer ran "hot". So I opened it up to replace the mouse pad and while inside the computer I discovered why the computer ran so hot. Look at the heat exchanger in the back left corner in the picture below.
A trick in opening it up is that two screws that hold the LCD screen on are hidden behind small round covers on the back of the computer. Other than that it opens up fairly easily.