Very powerful warning! One of my high school classmates died of smoke inhalation, when someone else in the building fell asleep while smoking. Joined smoke detectors would have woken her in time.

Since fire extinguishers have a lifespan, after which the charge is no good, you can also take the opportunity to practice using them when they're about to expire. Fire safety tests have shown that most people do not know how to operate a fire extinguisher... how far away to stand, whether to fire short bursts or one continuous stream, where to aim, and even how to disengage the safety pin.