The safe temp stated by the Nvidia specs are 83 degrees celsius when throttling starts. The card will stop working at 92 degrees celsius to prevent any damage. Usually those chips can withstand 100+ degrees before any damage so you should be safe. If you like to do crypto currency mining or mashine learning, set the max temp (point where the software throttles down to cool the chip) to 82 degrees and you should always have full power. If you like a low noise gaming experience, play with the tempature curve in tools like MSI Afterburner while you stress your gpu with a decent benchmark (Heaven for example). The lowest possible noise should hold jour gpu under full load at 80 degrees after burning in for an hour.
Don't be afraid, you...