Cooling system

The modern cooling system has not changed much from the cooling systems in the model T back in the '20s.  Oh sure, it has become infinitely more reliable and efficient at doing it's job, but the basic cooling system still consists of liquid coolant being circulated through the engine, then out to the radiator to be cooled by the air stream coming through the front grill of the vehicle.
Today's cooling system must maintain the engine at a constant temperature whether the outside air temperature is 110 degrees Fahrenheit  or 10 below zero.  If the engine temperature is too low, fuel economy will suffer and emissions will rise.  If the temperature is allowed to get too hot for too long, the engine will self destruct