Which factors determine Time of Useful Consciousness (TUC)?

Time of Useful Consciousness (TUC) is primarily determined by altitude. As altitude increases, the atmospheric pressure decreases, which reduces the amount of oxygen available in the air. This reduction in oxygen can lead to hypoxia, a condition where the body does not receive sufficient oxygen to function properly. At higher altitudes, the time it takes for an individual to lose consciousness due to lack of oxygen decreases significantly.

While factors such as flight duration, cabin temperature, and weather conditions can impact overall comfort, safety, and performance in the cabin, they do not directly influence the physiological limits of TUC like altitude does. Therefore, understanding the relationship between altitude and hypoxia is crucial for flight attendants and other aviation professionals in ensuring safety and effective emergency response in the event of rapid decompression or altitude-related issues.