Acute Mountain Sickness (AMS) has never been far from the minds of the team during their attempt to summit Mount Aconcagua. It was deemed the most likely reason members of the team may not summit (before the weather kicked in!). We hear from Paul Harries, the team cameraman who was diagnosed with AMS during the climb and had to be flown off the mountain.

By Paul Harries

I have never climbed a mountain. When I was asked to film the team on Aconcagua I jumped at the chance and started preparing immediately. I found the kit preparation as equally time consuming as the physical preparation, but enjoyed the challenges of all aspects of the trip.

When we started the trek from Penitentes I felt good and - despite the extra weight of the camera equipment - I felt strong. When we arrived at Confluencia at 3500 metres, this was the highest altitude I had been so far and I instantly began to feel my breathing change as my body adjusted to the thinner air.

The next day we set off on an acclimatisation hike. I travelled much lighter for this day and moved slightly quicker, although on the occasions I did attempt to push ahead to film the teams approach - I found myself completely out of breath and dry heaving for a few minutes at a time! It was apparent that even at this altitude, running would not be an option for me. At this stage I felt mildly light-headed and slightly lethargic, but was looking forward to getting to Base Camp at Plaza de Mulas the next day.

The day started off well with bright blue skies. The team were of high spirits and moving well. I, again was carrying a relatively heavy load for a day sack as I had my camera, batteries, and some other equipment I couldn't risk on the mules! There quickly formed two groups of hikers, the fast paced group and the slower paced group (of which I was definitely in the latter!) James and Adam hung back with me for a while to chat as we walked, although it quickly became obvious I could not answer them in conversation, but could only make breathless one word contributions!

This was when I started to get worried as the difference in our breathing made it obvious - my body had not acclimatised. the 20km hike was estimated to take around 8 hours. After a few hours into our day I was far behind the group, with the guide Nico and my teammate Mark staying at my pace (Nico for my safety, and Mark I think could enjoy the scenery a lot more this way!).

I met up with the group for lunch behind a massive boulder to shelter from the wind. At this stage I was 30-40 minutes behind them and was struggling for breath at every step. After lunch things went really downhill, as we climbed higher I could only take two or three steps without stopping and wheezing as if I'd just sprinted 200 metres. Nico and Mark split my gear between them and forced water and sugary sweets down my throat at each stop.

The pace must have been painfully slow for them. Every 5 minutes we had to stop for at least two, and after 8 hours I was struggling to stay awake when we stopped. At around the 10 hour mark I fell asleep mid-stride and fell over a boulder cutting my leg slightly. By this point I was also experiencing mild hallucinations and thought I saw other members of the team walking beside me - a very surreal experience!

We kept going though. I followed Nico and Mark who worked hard to keep me alert and motivated despite my body having other ideas. We arrived at Basecamp at 7.15pm, nearly 12 hours after we set off. I slept for at least 10 hours that night, but woke up disorientated and tired still. I spent most of the day resting, although we did have tent practise that I did not want to miss!

The doctor saw everyone at 1800 and was evidently concerned with my condition. Our lead guide Andy monitored my levels through that night. At one point my blood oxygen levels dropped into the 50s which is very low. In the morning the doctor made the decision to fly me off the mountain due to the risks of me developing pulmonary edaema. By this point I didn't have the energy to tie my shoes so looking back it was obviously the right decision, but I was gutted. Not because I wouldn't be able to summit (after all until I was asked to do this expedition I never had the urge to climb a mountain and had never even heard of Aconcagua!), but because I wanted to be with the team when they summited and tell their story as completely as I possibly could.

They are the most inspirational people I have ever come across and so to miss their most challenging times and how they deal so incredibly with diversity is not only my loss, but the loss of everyone who would have watched the results. All is not lost however, and the team were loaded up with gopros before my departure so I am hopeful good things will come of it.

I would like to thank the entire team for their support, and especially Mark for helping me through that horrendous day to Base Camp! Also Nico for guiding me during that time and Andy for keeping an eye on me at Base Camp. I understand the team are now in the process of coming down off the mountain and I'd like to wish them a safe descent.