Just a note, when you are monitoring temp issues in your PC, you need to monitor everything, your video card, audio card, any other card, ambient case temp, cpu temps, hdd temps, northbridge / southbridge temps, motherboard temps, etc. I'm just trying to make sure people understand that the video card isn't the only component in a computer that can overheat.
In one scenario, the heat from my video card was venting down onto my motherboard because, while I did have enough heatsink cooling, I didn't have enough venting to displace all the heat. So all the heat would cause the southbridge (i think) and it's very shitty heatsink to overheat. If you've bought a recent motherboard, you'll notice a lot of the southbridges now come with massive heatsinks and heatpipes that come down from the CPU. The fact that this design has become more and more standard, makes me think a lot more people than myself have run into this problem.
Now, this doesn't necessarily make me believe Bloodlines of all games is causing your problem. So why would an nVidia card break on 1 game? Here is 1 tip to get your mind thinking, nVidia writes game profiles in their drivers, if they detect a certain exe file or a certain hash (I forget what they use now) then it programs the card settings to act differently based on this. This allows them to tweak the game and hopefully have it run better on their cards. However, it is possible that the 'tweaked' settings for Bloodlines actually causes problems with all the patching that occurred for it. I'm not sure how to test this, maybe you can eliminate the profile for the game or rename the executable not sure.