Not sure if this was mentioned before but the overheat is most likely caused by the game requesting to render too many frames per second. That's why some areas you get a really really hight temperatures while others are just fine. You can check your current FPS in game by pressing Shift+Ctrl+F, it'll display in lower-left corner of the screen in tiny letters.
One solution, that I've been using to keep my GF 560GTX AMP! cool-ish, is to use an app to manually regulate the fan speeds.
Also, while not my favourite solution for many reasons, enabling the game Vertical Synch option seems to help a lot.
Other than that and hardware-related solutions you could try using a third-party application for frame limiting, or wait till your card's chipset manufacturer adds it to the driver options (nVidia promised to do something like that in the coming updates).
Hope this helps!