Abstract: The invention provides a fire extinguisher horn having an inner tube, through which gas may pass from the nozzle of the fire extinguisher to the atmosphere, and an outer tube surrounding the inner tube to form a chamber around the inner tube along at least part of its length. The chamber provides an insulating space between the inner and outer tubes so that, although the inner tube may become very cold in use as the extinguisher gas expands through it, the outer surface of the outer tube remains closer to the ambient temperature. Thus, it is possible to hold the extinguisher horn safely. Preferably, the horn further comprises apertures that allow atmospheric air to flow through the chamber when the extinguisher is in use, maintaining the temperature of the chamber and, hence, of the outer tube close to the ambient air temperature.