Just edited my post to include ...

Remove power cord.

Remove battery.


Yeah, depends on your environment, but typically after 6-8 month in our household, on the laptop I get something similar to this walkthrough - not my machine here, but the picture just after Step 6. is typical of the carpet I mentioned ...

http://www.insidemylaptop.com/clean-replace-cooling-fan-dell-xps-m1530-laptop/

I have seen carpets thicker than that inside the fan/vents, and sometimes a blow through just will not shift it (depends what all that microscopic gunk is mixed with as it builds up over time).

Symptoms: Case warm/hot to touch (more so than usual, and becomes consistently warm/hot), fan speed and noise increase getting more regular - And if you leave it too long (probably within a week) your machines auto-shutdown to protect itself against the heat will start occurring.
If you havent cleaned out your vents within the last year, dust is a strong contender on laptops for problems.

I would give the compressed air with a long bristle brush a go first though before trying my more drastic method .. I just like to be sure it has had a good clean out when I do it, and you cant really see inside to be sure on my machine.

Problem solved. I got a new fan for my computer to go under it and it works fine now. My old fan was filled with dust and it was probably blowing it into my laptop to make it worse.

I strip my system back to chip,though i don't use air or compressed,i use cotton buds n keyboard jel to get at the fans as the blades always get a coating of house oils on their tips resulting in a massive buildup of lint,dust.My room is prone to be situated where all the house heat goes to so cooling is a priority for me.I should get a small ac unit for the front intakes,i've got the case up close to the open window as outside temp is always cooler than inside my house,i have a cpu watercooler so the rear of the machine is where i concentrate on keeping clean.

Keeping them spik n cool gives them long life.

Sharn, glad to see you got that fixed. Years ago, I remember what even a passive "cooling" pad (it just lifted it off whatever surface you had it on) did for my laptop; it was night and day.
For anyone with similar issues, arlt3rn1ty's post is spot-on. Opening up a macine can be intimidating, but with the proper instructions, tools and patience you can keep a system running very well for a long time. I gamed on my old laptop for 7 years, swapped out a harddrive and sold it for $100 (he really shouldn't have paid that much).
I'll echo what many have said and and also say that if you don't absolutely NEED it to travel with you, build a desktop rather than buying a laptop. You'll get WAY more for your money, learn some things and even be able to re-use the case for your next machine if you get a good one.