disposed about the housing 200 in a manner to selectively warm the liquid in chamber 208 if the ambient temperature is below the freezing point and formation of ice is possible and or has occurred during periods of non use as previously described if the liquid has frozen the heating element 222 is operated for a given period of time to melt any ice before the gas generating device is rendered fully operational the operation of this embodiment is essentially similar to the first one and is such that upon ignition of the pyrotechnic charge 204 the combustion gas pressure acting on the piston 206 will drive it toward the burst disc 214 and create a hydrostatic pressure in chamber 208 sufficient to breach the disc this of course permits liquid to flow through the passage 210 to the nozzle arrangement 212 and to be entrained in a high speed flow of combustion gases which have breached the second burst disc 220 and which are emitted via the orifice in the sonic orifice plate 202 due to the high speed fluid flows the liquid becomes highly atomized and mixes with the hot combustion gases in the mixing chamber 216 in a manner which causes the formation of steam and reduces the temperature of the hot combustion gases it should be noted that while a multi passage passage structure 210 has been illustrated in fig2 a single passage may be sufficient if it is suitably dimensioned and arranged to direct a jet of water into contact with the high speed flow of combustion gas which is emitted from.