Thermostat

I have a 97 taurus and I'm overheating. I think it is the thermostat becuase I have a couple of the other symptoms as well (poor gas milage). I checked and there is no coolant loss. Only thing is that I shet the car down, let it cool dowwn, then the heat started working (showing that the collent is flowing). Could it be that the thermostat is working intermitantly and I just need to chagnge it out?

Is it just me or do these things seem to happen when its coldest?

Check to make sure the fan is working properly. Check the radiator for cold spots. When you say overheating, do you mean boiling over or just running hot? As far as the poor fuel mileage, when was the last time you had a tune-up? A poorly tuned motor can run hot. Spark plug color can tell you if you are running rich. Are you using oil?