These last days, there was a lot of talk about traffic ajms obsevred on the road to Mount Everest summit. They were the cause of several dramatic accidents in 2019, like in the previous years.
Most people would not imagine how challenging survival is at high-altitude, without even counting on the huge physical exhaustion from climbing and some always-possible medical pre-conditions.
To illustrate this, I offer you to check these videos showing some obvious effects of hypoxia (lack of oxygen), from mildly funndy to life-threatening. And external source of oxygen is mostly insufficient in 8000+m climbing.