The team had an oxygen training session today. They learnt how to fit masks properly to their faces, practiced breathing through them, learnt about dealing with blockages, adjusting the regulator and troubleshooting.
Our team will start to use supplemental oxygen around Camp 3, here the oxygen in the air is ~40% what you breathe at sea level. By the summit, it drops to only 33%. The extra oxygen makes a big difference to improve mental alertness, warmth and speed.