OK, as WVW mentioned, different things suit different people.
I'm probably a bit too blase about gas and fumes and fire, bc I've had a lot of experiences with all three. In fact, I'm irrepairably damaged by fumes and toxins that overcame me when I was working in a tunnel in Dagenham years ago. So I'm well aware of the consequences.
Again, I've seen the welder's bottles go on fire scores of times, and I mean right at the valve on the top of the bottle.
Also, one time near Fleet, when we were tunnelling under the M3, we were working in compressed air and a spark off the burner's torch ignited some straw we had down there ( to control the ground and water) and then set fire to the hydraulics ( oil) leading to the shield.
It was pretty scary and we only stooped the fire by shovelling the sand onto the flames. The worst thing was the fumes and the lack of oxygen. I wouldn't recommend it for a healthy life!
I suppose I should have been more comprehensive when I said about cutting the tube.
If you fear ignition, then nip the tube first ( fold it over to kink and seal) with one hand, then slice through the tube between your hand and the fire.
We never used to bother too much with that as our priority was to get the cylinder away. Those cylinders cost money and the suppliers mightn't be too happy if they're sent back with the paint burnt off.
Be safe; be lucky!
sean rua.
ps
You might want to spliff up before reading this bit ( from the truth about co):
" Carbon monoxide is present in all tobacco smoke and is a health risk that all smokers should know about.
Cigarette users inhale four times the carbon monoxide found in car exhaust. The smoke from one pack of cigarettes can raise the carbon monoxide concentration in a home to twice the Environmental Protection Agency (EPA) safety limit for outdoor air."
Don't have nightmares!