An open flame is a fire that is not contained or controlled by any type of container. You must always put your open flame out completely before leaving it unattended because an open flame can catch something on fire if left unattended for too long. Always extinguish an open flame using water, never try to put the fire out with dirt or sand because you might smother it and cause it to go out slower than normal which can be dangerous when dealing with a campfire etc.