Here's the recommended operating range for Core temperature:
80C Hot (100% Load)
75C Warm
70C Warm (Heavy Load)
60C Norm
50C Norm (Medium Load)
40C Norm
30C Cool (Idle)
25C Cool
Core temperatures up to 80C are safe.
Kaby Lakes tends to run a little warm anyways, should be fine if that's under load, idle at 65 would be pretty warm though.