Overheating

You may have an air lock in the cooling system or the thermostat has failed. try re-bleeding the cooling system, and it that is okay look at the thermostat.

how do i bleed the cooling system?

run the engine with the coolant filler cap off, as the thermostat opens up any air trapped should come to the surface it will bubble away and you may see the coolant level drop. if you can get the front of the car a bit higher jack it up or drive it up onto a gutter this can help as the air will want to make its way to the highest point, watch the coolant and if it drops just top it up so it is safe and you can see any bubbles. when the engine fans come on it will be at temperature and the thermostat should be fully opened.feel for cool spots on the radiator check for good heat at the heater and make sure the temperature gauge is sitting where it normally would be. if this is all okay you should have all the air out of the system. it is always good to recheck the next day as small air pockets can still bleed out and the coolant level may drop a little over night, see how you go doing this.

After you have tried what MHP said and it still has a problem then I would change the thermostat.