Fire in a building creates a tremendous amount of heat and smoke. It may seem like they're causing more damage than the fire, but in many instances firefighters must remove heat and smoke before they can get close enough to extinguish the fire. Because heat and smoke rise, cutting a hole in the roof and breaking out windows in strategic locations allows the smoke to vent upwards, allowing cool air to enter the structure from below. This improves visibility and lowers heat conditions for the firefighters inside, allowing them to quickly and safely extinguish the fire. Remember, heat and smoke cause damage too, so ventilation will actually reduce overall damage to a building and its contents.