structures are high-rises, and they’re the stoutest of all construction types when exposed to fire. High-rises are usually defined as buildings more than 75 feet tall, with some agencies making amendments for buildings that are 35–55 feet tall.structures are constructed of concrete and protected steel (steel coated with a fire-resistant material, most often a concrete mixture), and are designed to hold fire for an extended amount of time in order to keep the fire at bay in the room and/or floor of origin. As far as the typical ventilation operation of getting on the roof and cutting a hole, that’s not really an option when dealing with Type 1 construction. Even horizontal ventilation becomes challenging, as the windows are thick, tempered glass and may not be an efficient way to ventilate the structure. Ladder companies must be aggressive in securing the stairwells for both firefighters and victims evacuating the structureLadder companies must be aggressive in securing the stairwells for both firefighters and victims evacuating the structure. If the structure meets building code, it will be equipped with self-pressurizing stairwells and have HVAC systems that will aid in air movement. If necessary, the ladder company may need to mechanically pressurize the stairwells using a series of fans strategically placed at the base of the stairwell and every 10–12 floors depending on the effectiveness of the fans. The fire protection and fire-related systems in these buildings are overwhelming, so crews should make it a priority to locate a maintenance worker and keep them close throughout the incident.