A Few months ago we had a structure fire after a snow storm with temperatures in the lower 30’s. I was operating our 2nd due piece and laid the water supply for the fire. Once my job was completed I assisted the first crews with changing out air bottles etc. Due to the cold temperatures and the fact that most of the operations were defensive we had a thin layer of ice on all the components of the air packs. We are currently using Scot Next Generation 4500 air packs with the quick connect on the back. This particular time I was changing the pack on my Lieutenant as we have done many times before. The bottle released, I released the strap exhcanged with a new cylinder and here is where it gets interesting. I placed the new bottle in the pack, connected it and the pack announce the bottle was seated in the pack correctly. Then I secured the cinch strap before turning it on. Something told me to put my left hand on the neck of the bottle before openning the valve so my Lt. could go back to work and thank god I did. Once I openned the bottle the bottle became disconnected from the pack and the 4500 psi bottle shot up at me towards my face. I was lucky enough to hold the bottle down and only get a strong breeze in my face before I was able to control the bottle and turn it off.
We checked with Scott as to why this might of happenned and the only reason we could get was ice potentially building up in the connection housing. From this point foward when weather is that could we put the enitre pack in the cab of the truck to defrost prior to changing the bottle out if possible.