There are several reasons a 2002 Jeep Liberty could overheat. Some possible reasons are low in coolant, a bad thermostat, or the head gasket went bad.
The combustion process cause the engine to heat up.
Heater coil could have went out.
that's a bad sign of engine trouble.
Replace the Blower Resistor which is located behind the glove compartment. This is a common problem.
Combustion is the chemical reaction that causes a car engine to work. It is produced by fuel combining with oxygen which causes pressure and heat to turn the crankshaft of the engine. This essentially gets all of the parts of the engine moving.
It is under a heat shield on the back of the engine, above the oil pan.
Friction causes heat. Heat is a source of energy.
A faulty temperature sensor can cause the ECm to think your engine is overheating, this turning the heat light on constantly. You should make sure that your engine isn't in fact overheating though.
combustion and expansion
There still a lot of heat in the components of the engine, but the cooling system is not circulating coolant and no air is blowing past the engine. So just like the temperature of the turkey you take out of the oven keeps rising because of residual heat the temperature of the engine goes up for a little while after you turn it off.
difference schematic diagram between carnot heat engine and heat engine
Heat Engine Heat Engine