What going on Bricksters?

Today my girlfriend was explaining to me that the temp gauge had went up to "red section" and then back down to like below 9 o'clock position. When i went to the car to start her up,i heard that sound that is usually associated with the water pump going bad.So I popped the hood and looked at the water pump and noticed that there was some anti freeze sitting right on top of the water pump.I then checked the pump to see if there was some play but it was pretty secure.There was no puddle under the car. I started the car again a few hours later and i did not here that wierd sound. I think it might be the thermostat but i'm not too sure. My girlfriends says that it has been running cold except the last time she drove it when she said that the marker rose to the red section. I was thinking that the t-stat is in the open position. The heat does get pretty warm. I am stumped. Any more diagnoses i can do here at home before taking her into the indy volvo shop? Thanks for all the responses.