What does sucking or puffing of smoke from an open door or window indicate?

Sucking or puffing of smoke from an open door or window is an indication of explosive growth within a fire scenario. This phenomenon often occurs as the fire reaches a stage where it is rapidly consuming available fuel and oxygen, resulting in a significant increase in heat and pressure. When the door or window is opened, the fire's intense heat creates a vacuum effect, drawing air and smoke towards it. This behavior suggests that the fire is in a critical phase, potentially leading to a flashover if not properly controlled. Recognizing this sign is crucial for safety responders, as it helps them anticipate the fire's behavior and make informed tactical decisions. Understanding smoke movement and its implications can prevent dangerous situations for firefighters and aid in effective fire suppression strategies.