Life at Everest Base Camp (EBC) has been great, but our thoughts are focused firmly on the acclimatisation process i.e. getting used to the low oxygen levels.
EBC is located at 5365 meters, which means 6.5 times the height of Burj Khalifa, the tallest building in the world, and there's only about 50% of the oxygen compared to sea-level, which we're reminded of every time we try to do something strenuous like taking a shower as we lose our breathe very easily!
The low level of oxygen is not only a nuisance but also a constant danger to everyone.
Just days ago, a young Sherpa from another expedition developed High Altitude Cerebral Edema (HACE) and High Altitude Pulmonary Edema (HAPE), our two most significant medical threats on the mountain, and died in his sleep.
At the summit of Mount Everest, the amount of oxygen in the air falls to about 30-35% compared to sea-level, which is not sufficient to support human life.
In fact, if you magically flew a helicopter to the summit and dropped off a person there, that person would die within 30 minutes.
Some climbers still push their limits and try to summit Everest without use of supplemental oxygen, but most fail because the effort is simply too much for one's body to cope with.
Although my entire team will use supplemental oxygen on the summit bid, i.e. we'll breathe a mix of the ambient air as well as pressurised oxygen from bottles similar to SCUBA diving; we still have a long way to go before our bodies are ready for the challenge posed by the high altitude environment.
In light of this, we've been doing acclimatisation rotations on the mountains.
These rotations involve us moving up to high camps, spending a couple of nights there to shock our bodies with the low oxygen levels and then returning back down to EBC to let our bodies recover.
Each acclimatisation rotation requires us to pass through the notorious Khumbu Icefall, a collection of crevasses between two mountain faces complemented by regular avalanches including snow, ice and rocks.
The path through the icefall requires crossing over dozens of deep crevasses, using ladders tied together.
However, due to the instability of the icefall, the path through it changes almost daily as the glacier moves making the ladders unstable.
Fortunately, a group of Sherpas, called Icefall Doctors, look after the route daily to ensure it remains as safe as possible for the climbers heading up the mountain. However, I can assure you that "as safe as possible" is far from "safe".
We have a total of four high camps on the mountain.
We recently returned from a rotation during which we slept several nights at Camp 1 at 6150m as well as Camp 2 at 6500m.
Especially during the nights at the camps, most people, including our Sherpas, started developing signs of Acute Mountain Sickness (AMS), which, if not treated, can easily develop into life-threatening HACE or HAPE.
During the rotation, a Sherpa from another expedition fell into a crevasse and lost his life, providing yet another reminder of the constant dangers surrounding us.
We're currently enjoying a few days of rest at EBC before we start our last acclimatisation rotation on the mountain. We'll spend several nights in both Camp 2 as well as Camp 3 at 7400m, before returning back to EBC to wait for a suitable weather window to open for us to start our summit bid.
The summit bid i.e. the round-trip from EBC via our four high camps to the summit of Mount Everest, at 8850m, and back to EBC will take 5-6 days even for the strongest climbers, so weather plays a crucial part in our plans.
During a normal climbing season, the weather window during which Everest can be climbed is about two weeks, so we need a bit of luck to get our timing right on the mountain. So please keep your fingers crossed for us to have good luck!