Do not use Compressed air to clean out your laptop. This is the worst thing you can do. Using compressed air on the vents blows dust back into the laptop increasing the likelihood of failure.
If you wish to clean it, then take off the base of the laptop and carefully use a vacuum cleaner to remove the dust with a crevice tool or purchase a set of mini attachments that can be pruchased off the net. Failing that use some artists paint brushes to dislodge the dust and then use the vacuum to remove it.
If you do not feel confident doing this, then take the laptop to a local computer specialist and ask him to do it for you.
Download Fanspeed (
http://www.softpedia.com/get/System/System-Info/SpeedFan.shtml) to check that machine's internal temperatures and compare them to the processor temperature range for your machine.
If you are still concerned with the temperature of your laptop, then look around for a cooling stand for it. There are a great number of these and most plug into a spare USB port. I've found them very effective at heat dissipation.
Snibborg.
