What allows for controlled escape of heat, smoke, and gases in vertical ventilation?

Making openings in roofs or upper levels is crucial in vertical ventilation because it facilitates the escape of heat, smoke, and gases generated by the fire. This method effectively reduces the pressure build-up within a structure, allowing for more efficient removal of hazardous smoke and superheated air. By creating these openings, firefighters can create a pathway for the hot gases to rise and exit the building while simultaneously allowing cooler air to enter at lower levels. This not only helps clear the atmosphere for safer operations inside the structure but also aids in controlling the fire's behavior by reducing its intensity. Effective vertical ventilation is a strategic approach to enhancing safety and improving visibility, ultimately supporting fire suppression efforts.