What is one aspect of high-rise fires that is especially draining of energy?

Walking up many flights of stairs in personal protective equipment (PPE) is especially draining of energy due to the physical demands it places on firefighters. High-rise buildings often require emergency responders to ascend multiple flights of stairs to reach the fire's location, particularly when elevators are out of service or unsafe to use. This strenuous activity is compounded by the weight and bulkiness of the firefighting gear, which significantly increases the physical effort required. The combination of physical exertion and added weight can lead to quicker fatigue than would typically be experienced in other firefighting situations. This energy drain is critical for firefighters to manage, as it can impact their performance, decision-making, and overall safety during operations in a high-rise environment.