Besides that, it's no different than an engine. When air, or coolant, is flowing, when an object is at a certain temperature, it maintains that object at a certain temperature based on the amount of coolant or airflow. If you shut off the flow of air or coolant at the same time you shut down power or stop the internal combustion process, temperatures will go up for a period of time since there is no longer a source of cooling to carry exchanged heat away from the object in question.
Really, it's not much, if any, different than how foods continue to cook even after they've been removed from the heat source, which it's recommended to remove most meats slightly sooner than when they are actually done and then allow them to rest. That allows the continuation of the cooking process to complete and not result in an overcooked product.