65c for mining isn't too bad.
Generally you want to stay under 70c...
Here's a nice read, and graph about GPU mining and safe temperatures, https://cryptovoid.net/safe-mining-temp/.
"Temp Zones
0C – 29C Is the thing even on?
30C – 49C Idling. No major tasks are running. You’re probably checking your email, or scrolling around on Twitter.
50C – 59C GPU is idling in a warm room, or working around 50%. You tell me?
60C – 69C There’s action happening, and it’s getting a little warm. This is where you want your temps to be.
70C – 75C Okay things are getting pretty toasty. High graphics gaming or optimized mining. We definitely should not get any hotter.
75C – 79C This is the danger zone. Some graphics cards will be semi-ok with this… But, it’s not worth risking it.
80C – 89C Like playing with fire. At this range, your GPU might seem like it’s doing fine, or you might smell burning plastic. Either way, you are deducing it’s life-span quickly.
90C – 99C There’s definitely some damage happening. You might want to get the fire extinguisher.
100C – 109C If you’re lucky you can use your GPU after it get this hot, but treat it nice like an abused puppy.
110C+ Congratulations, your GPU is now a paperweight. However, let it cool off before you hang it on your wall."