Overheating could be a number of things.

Not sure how the stats are on these engines, but on my old Punto GT, the seals used to go and so the stat would be open all the time, causing the engine to never get up to temperature.

But if the stat were to stay shut or only partially open, it could obviously cause overheating.

Whipping the stat out and sticking it in boiling water to see if it opens and check the overall condition of it would be first on my list if I was trying to sort the prob.