Sounds like your thermostat isn't opening up.

If it stays closed you can't get any heat inside the car b/c no hot coolant is flowing through the heater core, and it can't flow through the radiator to cool the engine.



If you temp. gauge ever gets near the red mark, and you can't get any heat (which could help cool it down), you should shut the engine off before it gets to the red if possible. Even if you're on the road, just pull over, open the hood to vent more heat, and wait a while until the temp. has dropped some before you try it again. You can do that over and over (though not the best for the engine) if you have to in order to get home, etc. just as long as you don't run the engine while it's in the red. (on some cars the temp. gauge can actually continue to climb some after it's been shut off, meaning it might climb higher and hit red before it drops, as long as you've turned the engine off before that happens you should be alright).