In addition to the performance of their regular and ordinary duties, it shall be the duty of all police officers and firefighters at all times, and under all circumstances, to go to the aid of all persons, animals, or property in immediate distress or danger in the city, and to render such help and assistance as lies within their power. They shall also render such assistance outside the city limits as ordered by the police chief or by the fire chief. (1962 Code § 2-6.402)