The main problem faced by trekkers is trying to climb too quickly. From a medical perspective we will be trekking to a relatively high altitude (5,610on summit day). In order to ensure the comfort and enjoyment of all participants we will trek at a slower pace to allow our bodies to acclimatise. At sea level, the standard barometric pressure is 101kPa. At5,610mon the summit ofMount Damavand, the standard barometric pressure is 52kPa. This lower oxygen pressure means that there are fewer oxygen molecules in the samevolume of air - there is only 51% 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.The use of days dedicated to acclimatisation will ensure that your body adapt to the higher altitude gradually. We recommend that you discuss with your GP the option of using Diamox (acetazolamide) to help prevent Acute Mountain Sickness (AMS).