Acclimatising To Mont Blanc One of the main problems faced by climbers is trying to climb too quickly. From a medical perspective, we are climbing in very high altitude (up to 4,810m). At sea level, the standard barometric pressure is 101 kPa. At 4,810m on the summit of Mont Blanc, the standard barometric pressure is 57 kPa. This lower oxygen pressure means that there are fewer oxygen molecules in the same volume of air - there is only 56% of the oxygen available compared to sea level. Your body reacts to this lower oxygen level in a variety of ways - for example, your respiration (breathing) rate increases, and your body starts to generate more red blood cells. The respiration increase begins immediately, but the production of extra red blood cells takes longer. We are climbing a 4,000m peak before attempting Mont Blanc and have programmed an extra night at Rifugio Chabod. This will help ensure that we give our bodies more time to acclimatise to the lower oxygen levels before summit day. We recommend that you discuss with your GP the option of using diamox (acetazolamide) to help prevent Acute Mountain Sickness (AMS).