Most victims of fires are killed not by the fire itself, but by the smoke. The smoke created by a fire can fill whole rooms and areas within minutes and quickly becomes a death trap. It not only causes serious smoke inhalation, but also greatly reduces visibility and makes it more difficult to escape from the danger zone in time. On top of loss of orientation caused by the lack of visibility comes impairment of the senses caused by the toxic fumes.
In order to prevent this, smoke and heat extraction ventilation systems direct the smoke away before it cools off under the ceiling and sinks back down to the floor. The largely smoke-free zone achieved in this way provides not only the air that people need to breathe to stay alive, but also preserves their ability to get their bearings and helps to avoid panic. Zones largely free of smoke also assist the fire service in quickly localising and extinguishing the source of the fire.