Abstract: A portable, self-contained protection device includes a battery operated combustion product sensor and intrusion switch, providing energization to an audible warning device, all contained in a casing adapted to be mounted, for example, such as on a door. A spring biased retainer maintains the warning device in its mounted condition. Two forms of intrusion switch are disclosed, both of which have opened and closed conditions. When the warning device is mounted on the door, and the door is closed, the intrusion switch is maintained open, however when the door is opened, the intrusion switch closes, providing energy to the audible warning device. The combustion product sensor, likewise, provides energy to the audible warning device, upon sensing products of combustion. Auxiliary devices include an optical indicator issuing a light signal whenever the audible warning device is actuated. An external actuator may also be employed to actuate the warning device.