Hello Guys!
I had the same problem but I found out how to fix it after a while.
It all started when I got the Asus HD7850 V2, I was playing Hitman Absolution maxed out when the screen flashed and got all distorted (The grey image someone posted) the temp reached 71c. Happens that these cards have a high temperature by nature mine idle gets around 32c/33c and playing games with maxed out settings really insane temps and I have a corsair H60 liquid cooling plus 2 cooler master jetflo at 1600 rpm on the lateral, so it's not my cooling system at all. Tho there is a simple way of preventing this...by creating profiles on asus GPU tweaks.
This is what you should do...
Install Asus GPU Tweaks
Create 2 profiles
1 should have the default values
The other one must have the default values except the fan that should be at 100% (this one is for gaming)
Go into settings and activate the hotkeys option.
From now on, everytime you feel like you want to play you need to activate the profile with the 100% fan setting, in my case Ctrl + Alt + 1 is the gaming one Ctrl + Alt +2 the normal one. So basicly switch profiles everytime you want to play so your fan gc doesn't works at 100% all the time.
After this my GC doesn't even reach 60c playing high graphic games even for hours!