I had to repair one of these recently Donna. As the others have said, most likely the fan isn't working. The one I looked at turned out to be a loose connection (VERY lucky - easily fixed)
One thing that does happen with these, is that the fan is simply stuck. When you think about it ....... 20 years of dust and grime. All I can suggest is to get inside (turn the power off first) and poke the fan blades with a screwdriver to see if they're free.
Wish I could do more to help.