you also need to carry a 2Kg fire extinguisher,
It's so that you can be sure to put out any fire started as the result of a crash before the emergency services get there so the cylinder doesn't heat up too much
Opening a hot or heated cylinder isn't an option, the first one is to put the fire out, secondly, do you always carry your cylinder key to open the cylinder and can you find it quickly enough?
Thirdly, can you aim the cylinder at the fire to put the flames out?
It's easier to use an extinguisher