Aspire 3000 overheating

Hey all, I am currently using an Acer Aspire 3000, and I've had some problems with it overheating. When I first got it I used it on my bed and it got very hot, so I figured the vent underneath was being blocked, and since then I always rest it on a large hardcover book so it's like it's on a table or something. However the bottom of the notebook gets extremely hot. Right now if I lift the laptop up and touch the underneath it's hot enought that it hurts my hand. The fan is on at a medium speed now, but the thing is, I'm not using any demanding programs, just internet explorer, messenger, and my virus scanner is running in the background.

What could it be which is causing this overheating?

 

could u be specific ....why dont you check the temperature of your harddrive,processor and gpu and post it for checking the temperature use a software like everest or nhc as it will be helpful in detrminig the problem of your notebook

 

If you can,
A recovery will be good.
How long have been since you bought it?
It might be the dust collected in it.