Yea generally speaking all nvidia cards run hot and 80c is a normal temp now a days for nvidia. It shouldn't even be causing you to lock up though. I think an unstable overclock is more likely the culprit. Or some other thing, not ruling out bios based overclocking/hardware issues or anything I might of forgotten lol..
Buy an aftermarket cooler and put it on as well.. not hard to do.
Or take the case off the card and put a fan right next to it..

and +1 reference models are what we generally want. They don't mess with the original design so we can overvolt and overclock.