Abstract: A self-activating fire extinguisher which is particularly useful as a Christmas tree ornament is comprised of a thin-walled sealed glass container having a quantity of a fire extinguishing liquid such as Halon 2402 contained therein. When in the vicinity of a fire, the temperature of the liquid will rise causing it to boil which increases the pressure within the container. Eventually the container will break, releasing the liquid; the fumes from which extinguish the fire. In order to prevent glass fragments from being thrown about when the container breaks, the majority of the container covered by a metal shell. This shell is adhesively secured to the glass and maintains the broken pieces of glass together even at high temperatures. The liquid and fumes are released through a small portion of the container that is not covered by the shell.