Fires are very unpredictable.
Sleep with bedroom doors closed. A closed bedroom door, even a lightweight hollow-cored door, provides protection from smoke and heat. For this same reason you should always close doors behind you along your escape route as you evacuate your home during a fire. Ensure everyone in your household recognizes the sound of the various smoke alarms. Each and every person should be able to hear the smoke alarm in his or her sleeping area, even with the doors closed.