Abstract: A portable thermal image emergency exit marking device for use by firefighters and rescue personnel includes a polygonal housing having electrical heating elements on side panels that are shaped to form infrared heat generating words or symbols indicating an escape exit which are clearly visible by a thermal imaging camera, a flashing strobe light, and an audible alarm, to guide firefighters to the exit of a burning smoke-filled building. The configuration of the infrared heating elements avoids confusion and clearly distinguishes the words or symbols from other hot spots, heat emitting objects, and burning objects in the environment of the burning structure. An accessory adjustably supports the marking device at various heights above the floor surface when desired. The housing may have a ring for connecting a rope that can be extended from the housing to an exit of the burning structure and followed to exit the burning structure.