Yeah pretty much same thing on mine, did it start overheating when it was going though? Mine is boiling whenever I have a look under the bonnet when my car starts overheating (When it starts over heating I turn the car off but leave the key on so the fan keeps going, I turn my heater on full and I open the overflow which spills its guts in my engine bay). It usually cools down to normal temp quick.
Sometimes I can turn my heater on full and keep driving and it settles itself.