Breaking window glass to make entry into a building can be hazardous because it may create flying glass shards and:

Breaking window glass to gain entry can indeed alter the flow path of smoke and heat within a building. When a firefighter breaks a window, it introduces a new opening which can change the dynamics of airflow. This newly created opening can allow smoke and heat to escape more freely, which can significantly affect the conditions inside the structure.

Firefighters are trained to understand that smoke and heat naturally flow toward cooler areas, and by breaking a window, the previously enclosed atmosphere inside the building is altered. This change can either assist in ventilating the fire, making it safer for the occupants and firefighters, or it can inadvertently contribute to the rapid spread of fire if not carefully coordinated with other ventilation tactics.

Additionally, changing the flow path can also impact the overall effectiveness of fire suppression efforts, making it a critical consideration during firefighting operations. Understanding these dynamics underscores the importance of strategic decision-making when entering a structure under fire conditions, enhancing both safety and efficiency in fire suppression efforts.