Half-Life 2 (plus episodes) have a tendency of crashing my computer

I've recently started plowing through HL2 and the episodic content (currently starting out on Ep 2), and have noticed a weird problem.

It seems that after an undetermined amount of time, my computer will crash. My computer is a notebook with an Nvidia dedicated graphics chip...its good enough to run HL2 and Fallout 3 (but as I'm away from it now, I don't have the specs handy).

I can combat this crashing issue by periodically alt+tabbing to my desktop and letting my computer relax for a bit.

On another note, my fans are completely clear when I play...airflow should not be a problem IMO.

On another another note, I have absolutely zero problems playing TF2 or CSS....TF2 will lag for me slightly if there is too much going on at once (i.e. 32 player mayhem), but no crashing.

Any thoughts?

---

edit

My graphics card is an Nvidia GeForce 8600M GT

From gaming espais

• Simply being able to periodically let your graphics card "rest", and the problem goes away, is a pretty clear cut case of a heat related issue. Being a notebook, it's tough to tell if dust is encasing any of your hardware, even if plenty of air still seems to be flowing out of the holes. Every notebook I've ever had has seemed to "heated up" with age, and the particular processes HL2 (and the particular graphics settings) may make this particular game more susceptible.

  I used to laugh at people that played on "cooling pads", but I've got a coworker that can now play Sims 3 at three times the frame rate she was getting before she bought it. It might also be worth a try to physically open the notebook, get to the motherboard (assuming an onboard chipset), and clear out any debris you see.

  If it's somehow a strange cache-related issue, there won't be much that you can do short of driver updates and tweaking graphics settings.

  StampedeXV : Also: maybe reduce settings for graphics. This will reduce amount of work the GPU has to do -> less heat. If it works then, you know it's either heat or power and not some software.

  espais : i'll go with this answer because it is probably the most likely...i will crack it open and see if i can give it a good cleaning
  From Jeffrey

• Heat is one answer. Another answer is Power. Your power supply is maybe not good enough to provide that much power for a longer duration. Maybe HL2 needs some extra watt.

  I still think heat is No #1 cause (see Jeffrey's answer how to handle that), but every now and then power supply is the problem.

  From StampedeXV