在4000米以上高度跳伞，空降兵会缺氧，而缺氧带来的后果是让人瞬间丧失知觉或神志不清。从电视画面上可以看到，15名空降兵并没有戴氧气罩。4999米高空，还意味着从云层上往下跳，这是空降兵最忌讳的，因为云层阻挡了视线，遮盖了地面的地形地貌，在不清楚地面的情况下，空降兵很有可能落到极其危险的地方，比如电线上、崎岖的山涧中、激流中。
However, the problem is: at the base camp at 5,380 m (17,700 ft) on the south side of Everest in Nepal, climbers don't wear 氧气罩, and they function quit well. Those climbers stay there for a couple weeks to adjust themselves and prepare for the climb. Why don't they "瞬间丧失知觉或神志不清"?
A typical HALO/HAHO (High Altitude-Low Opening/High Altitude-High Opening) insertion, paratroopers jump at the altitudes between 7600m and 11000m. A lot higher than 4000/5000m. A typical US paratrooper is trained for both dated back in the 60s. Before HALO/HAHO, paratroopers get prebreath of pure oxygen, however, for a 4000/5000m jump, that is not required. A normal healthy person won't have any problem in that altitude.