System slows down, then shuts down

[exploitations]

Hey everyone, I've been searching for days now but I can't seem to find ANYTHING that helps me with this problem, and I'm sorry if this has already been solved on the forums, but I can't find a post that will solve the issue.

Anyway, I have an Asus k52jc with ubuntu 11.04 installed. It's all up to date, and it's only been on here for a few weeks.
Until a few days ago, it started to slow down then shut down. Not just shut down instantly, but it actually goes through the shut down process.

I have no idea what's going on, and it's very annoying because I have projects I need to complete and my computer keeps shutting off.

Any help will be appreciated,
Thanks

[Linuxisfast]

Classic overheat issue, check your CPU usage and also check your vents for blockage, make sure your fan is working and also get a laptop cooler.