So why is Mount Everest so dangerous?
Eight thousand metres is a special line in the climbing world referred to as “the death zone”. While this is a very dramatic term, it means exactly what it says. If you go above 8,000m for too long, you will die, guaranteed. And just how long is too long? It can be anywhere between one to four days at the most. There are only 14 mountains in the world that rise into the death zone and Everest happens to be the tallest at 8,850m.
One reason altitudes above 8,000m are so dangerous is that the human body can no longer regenerate cells above this line. In addition, cells are dying at an accelerated rate. This is caused by a combination of oxygen deprivation and pressure changes, and by the way our body reacts to these changes. As our cells die and are not replaced, our body enters a “triage” state. It starts shutting down less important bodily functions by reducing oxygen and blood flow to the muscles, brain and extremities. This becomes a rapid chain reaction of events that, in turn, lead to a quick downward slide toward heart failure.
But, at altitude, other things are happening to your body as well. Your body is accustomed to operating in a pretty narrow range of atmospheric pressures. Once you go above around 4,000 metres your body loses its equilibrium. Due to the lower atmospheric pressure, fluids begin to leak from your cells, veins and capillaries. These fluids can pool in your lungs (pulmonary oedema) or in and on your brain (cerebral oedema). Both can quickly cause death if not treated, and the only real treatment is rapid descent to lower elevations where your body can re-gain its equilibrium.
If you are near the summit of Mount Everest and cerebral or pulmonary oedema sets in, you are in big trouble. It is unlikely you will be able to descend fast enough to alleviate the symptoms. The more it sets in, the more you become mentally and physically incapacitated, reducing your ability to descend even more. Affected climbers will stumble and fall off the route. They will make poor decisions. They will start to hallucinate and some will become combative to those who try to help them. It is a very frightening situation to be in.
Pure, simple exhaustion is also blamed for many deaths on Everest and the other big mountains of the world. By the time climbers start their summit bid they have usually been on the mountain for at least six weeks. They have not slept well for much of that time and they have lost a considerable amount of weight and muscle mass. They have likely not eaten much for days, and have burned tens of thousands of calories. They are far from the picture of top fitness, and now they must push their bodies harder than they have ever pushed. While the goal of reaching the summit is a very strong motivator, once it has been achieved, many climbers are unable to continue. Eighty percent of all climbers who die on Everest do so after reaching the summit. They die on the way down. They simply run out of gas, sit down, close their eyes and never get up again.
I have not even begun to discuss hypothermia, hypoxia, avalanches, snow and wind storms, extreme temperatures, rock and ice fall and the myriad of other potential dangers on Everest. The fact is that Everest is a bloody dangerous place and needs to be respected for the power it holds.