I have a 2005 Cobalt and have had issues for the last couple weeks that I ignored. Last night while driving, the coolant temperature went up to 240 degrees. I know nothinggg about cars, but that is way hotter than it has ever been. Also something is leaking onto my passenger side floor. Not just a small leak, but probably a half inch worth of liquid all over the carpet. Someone suggested it may be the heater core, and not to drive it at all. But another person told me it could just be water leaking inside from running the a/c and that it is no big deal. I know I should take it to get looked at, but didn't know how much monetarily something like this would cost. And since its Sunday I'd have to wait until tomorrow and I'm not sure if I should drive it today or not. Any suggestions?