How does a radiator cool the coolant?

A radiator cools the coolant by transferring heat from the hot coolant to the air outside the vehicle. As the hot coolant flows through the radiator's tubes, it releases heat to the metal fins surrounding these tubes. The airflow, generated either by the vehicle's movement or by a fan, carries away the heat from the fins, allowing the coolant to cool down before it circulates back to the engine. This process ensures that the engine maintains an optimal operating temperature.