Closing your bedroom door before sleeping can slow the spread of heat and toxic smoke into the room during a fire. Modern synthetic furnishings can burn rapidly, producing carbon monoxide and other dangerous gases that may overwhelm people before they reach safety. A shut door is not fireproof, and it cannot guarantee breathable air, but it can help preserve more survivable conditions while you respond. That is the practical message behind “Close Before You Doze.”

Make that habit part of a broader plan: install interconnected smoke alarms inside bedrooms, outside sleeping areas, and on every level; test them regularly; and practice two ways out whenever possible. If an alarm sounds, leave immediately using a safe route—never investigate or collect belongings. If smoke or heat blocks escape, keep the door closed, call emergency services, and signal from a window. Once outside, stay outside. Preparation tonight could protect the people you love.