Use this utility by EVGA:
http://www.evga.com/precision/
You can run this program with the Nvidia cards, no problem. In game, you can display all your temps and control fan speeds, also, clock your card. It is a nice utility. I use it just for FPS and heat readings while I play games. Check it out. Also, my Nvidia 9800GT runs about 55-60 degrees C when playing SH4 or COD WaW. So, yes your temps might be getting a bit hot.