Now this is very interesting.
I couldn't crash the graphics driver on Ballitic's Sandbox where I normally could do it within 2 minutes, now I was able to fly steadily for quite some time. Temperature rose from the normal 50'C I have on desktop to something around 65'C.
I started feeling overconfident so I went back to campaign to drive a truck with some guerillas and I saw the temperature sit nicely at around 70'C but the GPU Usage was bouncing around 60-80%. Then it finally started rising to 99% where I decided to pause the game. It showed no signs of decreasing so I continued on with the game but stopped the vehicle and turned of its headlights.
The Usage started to drop.
It decreased to around 80% before I tried to carry on with the mission but the driver crashed shortly afterwards with the log stating GPU Usage being 99% again.
Max GPU Temp: 77'C
I am no expert but I think that's within safety standards.