When car is sitting still and running after a few minutes the overheat light comes on and states car is overheated but you can turn the car off and back on and the warning light goes off. What is causing this?
Have you checked the coolant level?
Have you had your cooling system serviced? Needs to be done every three years.
Is the radiator fan running when you get the light?
The fact that the problem occurs so quickly and goes away immediately (no time for any significant cooling off) upon shutting off and restarting leads me to believe the problem is electrical in nature, possibly a faulty coolant temperature sensor.
More than likely that is true, but the potential for engine damage if there really is an overheating issue screams-out for a qualified mechanic to check and see the exact cause of the problem.
Does the engine fan come on?