Well, if I run it with no changes what so ever it runs at around 80 ° and now i noticed with the new driver from nvidia the second chip is now -slightly- working running at 52 ° instead of 32 ° resting temperature. The gtx 690 is -not- a maxwell gpu, so that solution will not work, it is kepler. What settings do you have your game running at? geforce experience has pretty much said I can max everything except for shadow draw distance. If you have your system running the game on the default settings the game sets when you first kaunch the game, then yes, mine would be running much cooler as well, but I tend to go with geforce experiences recommendations, unless it recommends 4k, then I drop it to 1080.
As for the massive problems, generally when playing games for extended periods you do not want temps that high, for a few minutes that is fine, but not for extended periods of time. I am no tech expert, but I know it will eventually kill your gpu.
I know my gpu is not having overheating issues, because it cools down -very- quickly, from 80° to 40 ° in less than a minute, and rests at around 32°, and I have done many of stress tests to check this, as I am paranoid when it comes to these things, all checked out fine.