Drinking of water

Here is my experience on the importance of drinking water, that I wish to share. I was 70 when I took my pilgrimage eleven years ago, to Gomukh, in the Himalayas. Gomukh is in the snout of the Gangotri Glacier, at 4255 M (13,960 ft), from where Bhagirathi River originates. After completing 14KM trek on the mule, from Gangothri to 'Bhojbasa' we were asked to continue four KM rough ride and walk on narrow bridle-path on boulders. Walking (jumping) on boulders make the route after 'Bhojbasa' quite difficult. One has to cross this boulder zone to reach near the Gomukh snout. After walking for some distance I felt difficult breathing and became disillusioned, every thing looked different,I could hear the thumping of my heart beat, and the bright reflected sun light, the crackling sound of falling of big glacier chunks in flowing river added to the confusion. I was feeling thirsty but not bold enough to drink the ice cold water running at my feet. I took rest on the big boulders and some how finished my pilgrimage, with the help of our group.

Well, on my return journey from New Delhi to Bangalore I met a gentleman returning after his training in the Nehru Institute of Mountaineering at Uttarkashi. I explained to him my experience in Gomukh. He told me that the hallucinating experience may be due to dehydration, which happens in such high ranges. And that it was important to drink lot of water while trekking at that height, where oxygen becomes rare.
Later when I read articles on this subject, I came to know this condition is called Acute Mountain Sickness (AMS) or Altitude Sickness and it occurs when you travel in high attitudes above 10,000ft.

A few lines to help others who go on trekking pilgrimages in The Himalayas.
Acute mountain sickness is due to a combination of reduced air pressure and lower oxygen levels at high altitudes.The causes of altitude sickness are not fully understood. When we move away from MSL up into higher altitudes air pressure gets lowered. Air at lower pressure has less oxygen per lungful. At lower air pressure, water evaporates faster. This can lead to dehydration. Dehydration due to the higher rate of water vapour lost from the lungs at higher altitudes may contribute to the symptoms of altitude sickness. Easy way to prevent altitude sickness is to give the body enough time to get used to the rarefied air. A slow and steady ascent is help a lot. Adequate hydration is a must. The body is constantly losing fluid from the lungs and the skin in the high, dry environment. Drink enough to maintain a clear and abundant urine output. Other measures include eating a high carbohydrate diet, climbing high during the day and coming lower down to sleep, and to mild to moderate activity during the day rather than just lying around are suggested to keep the body fit.
Nowadays I advise people to drink plenty of water while visiting places of pilgrimage in the Himalayas.