I don't know your laptop but it sounds like you have a lot of
dirt and lint inside the box making it hard for the fan to cool. I
have used a vacume sweeper with a lot of suck and the crud really comes out.
I find that an air compressor with a blow gun works well for me. Much
better than a vacuum cleaner for getting the muck out of all those
hard to get at little places I reckon.
Dave