Is it the stock cooling on the card? What kind of case cooling do you have? Definitely sounds like you need better cooling.
My Tyan Tachyon 9700pro only gets as high as 43°C while playing FarCry. And that was after a couple of hours non-stop. Water cooling has it's perks.
When I had the stock cooling on it, the highest I saw it was around 65°C. That is well within the safe area of the card though.