WE have just witnessed another deadly week in the most deadly of environments. The discovery of the bodies of two Indian climbers high on Everest on Friday has brought the death toll in Nepal to five in the current climbing season.

Paresh Nath and Goutam Ghosh from West Bengal had been missing since last Saturday in Everest’s so-called “death zone”. The grim discovery follows the death of an Indian climber on the same expedition, Subhash Paul, while Australian woman Maria Strydom, 34, and Dutch climber Eric Ary Arnold, 35, both died as they descended the mountain. A sixth climber, Sunita Hazra, also from the Indian expedition, has been airlifted to hospital in Kathmandu, where her condition is described as serious.

Activities on the mountain had settled back into a more normal rhythm following the double disasters of last April’s earthquake in Nepal, which killed 8,000 people (18 at Everest Base Camp alone) and the avalanche the year before which claimed the lives of 16 Sherpas in the Khumbu Icefall. However, these latest deaths prove that as long as people with limited climbing and altitude experience are allowed to push their limits in a bid to stand on the highest peak, we are going to continue to see deaths on Everest.

The first thing to understand about Mount Everest is that it is hit with hurricane-force winds 300 days a year. However, each year there is a short window, generally towards the end of May, in which climbers from all over the globe make their attempt at the summit. During this roughly two-week period, the monsoon sweeps in from India, bringing with it warm air and pushing the jet stream off the summit. It is these conditions that allow climbers to sneak up to the top and, hopefully, back down safely again. Unfortunately, every year people die trying because of a fundamental lack of understanding about how extreme altitude and low levels of oxygen above 8,000 metres will take its toll. Let’s start with the basic facts about the “death zone”. Above 5,500m, nothing lives and nothing can survive. Once you cross into this height, you are entering the lower realm of the death zone. In this zone your body is slowly dying. At sea level there is 100 per cent oxygen which our organs and muscles use to function normally. On the top of Ben Nevis, a mere 1,345m, however, the oxygen level is 88 per cent. Now this is not a huge issue at this height. In fact, some people can travel from sea level straight to 3,000m quiet easily. They may suffer only a headache or mild sickness.

Everest is a different world altogether. At base camp for instance there is just over half the oxygen in the atmosphere (53 per cent). On the summit, it is a mere 33 per cent. If you were to travel straight to 5,364m, the height of Everest Base Camp, you would be dead within 24 hours. If you were transported to the summit from sea level, you would last less than five minutes.

What needs to be understood by those attempting to scale the mountain, is that no-one can fully acclimatize to the low levels of oxygen in the death zone. Even if you lived at 4,000m, a full 1,500m below the lower reaches of the death zone, it would take your body five years to fully acclimatize.

I have personally been on over 35 expeditions above 5,500m and I was fortunate enough to stand on the top of Mount Everest in 2008. It took me years and numerous climbs to fully understand how I react to low oxygen. On the mountains that I did prior to Everest, I was sick numerous times and learned that my body needs a longer time at altitude to acclimatise. But when I give myself adequate time, and set the itinerary to match this, I was able to adapt very well and in fact completed my Everest summit without any headaches or altitude sickness.

We climbers who move above these heights are essentially playing Russian roulette with our lives, and while most accept these risks, it is vital climbers work to a schedule suited to their needs and not a one-size-fits-all itinerary dictated by the expedition they have signed up for.

Another common misconception about climbing on Everest is that the bottled oxygen allows a climber to breathe like they would at sea level. In fact, the bottled oxygen is a mixture of compressed gas and ambient air from outside the mask, which only adds an additional two per cent to their oxygen levels. This keeps them alive. It does not help them climb faster or better. If that oxygen runs out, then they end up in an environment they are not acclimatised to. When I climbed on Everest, I saw a climber go blind from lack of oxygen after his bottles froze and he was left without any supplemental oxygen.

There are so many factors on Everest that can kill you, many of which you have no control over. However, coming to climb Everest with the proper experience and knowledge of how your body works at high altitude can be the factor that can saves your life.

So far this year, there has been more than 350 successful summits on Everest, most of which are local Sherpa climbers. This climbing season has witnessed five deaths and 30 others have reported serious frostbite, ailments and possible life-threatening injuries due to the lack of oxygen. Unless the mountaineering companies operating on Everest and the Nepalese Mountaineering Association stand up and make sure adventurers have a serious climbing CV and previous 8,000m climbing experience, then every May the cycle of death on Everest is destined to repeat itself.

Ian Taylor Trekking runs trekking and climbing expeditions in the Himalayas and around the world. Find out more

at www.iantaylortrekking.com