Abstract: A self-contained automatic fire extinguishing device includes a container having container walls defining a container chamber for storage of a fire extinguishing agent therein. The container has at least one aperture through its container walls. The fire extinguishing device also includes a vessel having vessel walls defining a vessel chamber. The vessel is coupled to the container such that the container chamber is in fluid communication with the vessel chamber via the at least one aperture. The vessel also has at least one opening therethrough. A heat responsive closure/actuating element is coupled to the container for substantially selectably sealing the at least one aperture of the container to alternately prevent and permit fluid communication between the container chamber and the vessel chamber.