The overheating light comes on and the gauge goes way over into the red . and then about half an hour later everything goes back to normal.

SOURCE: overheating

Did you bleed the cooling system after refilling the radiator ? to bleed the system, fill the radiator with water and coolant. Run the engine until it is at a good temperature. Then turn off the engine and look for a bleeding screw at the oulet of the thermostat housing and turn it with a screwdriver counterclock wise. The trapped air will go out and coolant will start coming out. refill the radiator and repeat until only coolant comes out and no air.be careful not to burn yourself.

SOURCE: Temperature Red lining

Water Pump check radiator to see if fluid is moving

SOURCE: 2000 dodge durango 4.7

two probably thing , you have a pluged radiator or the fan clush is not good, if when you are cruising it doesn' t overheating , but when you stop for 2-5 minuts it does, then is the fan clush, if when cruising it overheating then is the radiator . all this thinking that you checked the cooland level and changed the termostat with the correct oness

SOURCE: temp gauge up and down

It is IMPORTANT That you Correct This ,as Engine Temp is Important. I Recomend the Coolant Temperture Sensor Be Replaced to Correct this.

SOURCE: 2001 grand caravan overheating. then suddenly cool

Change your thermostat before it sticks closed completely. Sticky thermostat is usually the cause.
Another possibility is that your radiator fan temperature switch is going bad. This is usually located next to the upper radiator hose at the gooseneck on your engine where the thermostat is located.