It seems to be something about the way the engine handles transparencies, that makes my video card temperature go straight into the stratosphere. Especially the island map screens on either game, the GPU temperature rockets straight to 80 degrees C, and slowly increases towards a fatal overheat from there. Reducing the resolution doesn't even help. Reducing detail works, but it has to be cranked clear down to 3 to avoid overheating.
The only other game that does this is STALKER, which I can only play in the winter with the heat off. Every other game I have consistently stays under 80 degrees, even Fallout 3 with every single graphics setting maxed (of course, the framerate is unplayable then).
I'm running Windows XP x64, and I'v got an Intel Core 2 Duo 6320 at 1.86 GHz, 2 gigs RAM, and a GeForce 9800 GT. I was running 185.85 of the drivers, and just updated to the latest ones (190.62). Still having this problem.