To limit the probability that temperatures on the unexposed side of a door in a fire separation will become excessively hot during a fire, which could lead to the ignition of material near the door, which could lead to the spread of fire, which could lead to harm to persons on the other side of the fire separation.
To limit the probability that temperatures on the unexposed side of a door in a fire separation will become excessively hot during a fire, which could lead to the reluctance of persons to pass near the door, which could lead to delays in evacuation, which could lead to harm to persons.
To limit the probability that temperatures on the unexposed side of a door in a fire separation will become excessively hot during a fire, which could lead to harm to persons who touch the door.