Just wanted to add that one of the worst things you can do to an engine is run it cold. 190 to 210 is a fine operating range for coolant (antifreeze mix). Excursions to 220 in certain circumstances are not bad.
Also - remember internal combustion engine is a heat engine that runs at poor mechanical efficiency. When you timing, mixture or compression is off your efficiency drops which means less mechanical energy and more heat energy - thus overheating when cooling system can no longer handle the situation.
