Quote Originally Posted by mikebarger
I don't understand the mechanics of it, but the intense heat rode right up over the cold CO2 and burnt his hair. He wasn't hurt, other than having shorter eyebrows for a cuple weeks. He too threw the bottle.
That is called "backflash".

The correct way is to aim the CO2 in front of and below the base of the fire, and sweeping up, slowly - cutting off the oxygen supply progressively - from the base up.

The way it was explained was that if you "blanket" the fire, it will search for oxygen by spreading rapidly in every direction under the blanketing cloud. Not technically accurate - but close enough in practice.