My Face Caught on Fire

A 55 year-old woman with severe emphysema connected her oxygen tanks to dozens of feet of extension tubing so that she could be outside her house while still on oxygen. To compensate for the extended tube distance, she had to keep her oxygen on very high flow. One day, a friend drove in from out of town to visit her. She ran outside to give him a big hug while sporting her oxygen tubes on her face. Ordinarily this would not be a problem, however, the woman's friend had a lit cigarette in his mouth.