By MARC SHAW
New Zealanders who take a break from summer to ski in the Rocky Mountains or trek in Nepal may well spend the first few days sympathising with the mountaineering experience of Prime Minister Helen Clark.
If the altitude is greater than 1500m there is less oxygen. Until you get
used to it you could find yourself breathing hard just doing up your shoelaces, and find that you have headaches, lightheadedness, fatigue and altered perceptions, and have trouble sleeping.
This is known as acute mountain sickness. Helen Clark probably suffered from some of these symptoms when climbing in South America.
Altitude can also aggravate underlying illnesses, particularly heart and chest disease. But there are some simple guidelines when travelling in mountainous regions.
Ascend gradually - that is the key to prevention.
Above 3000m, each night should be no more than 300m above the last stop, with a rest day every 1000m. This is a general golden rule and is not usually too difficult to manage.
Being fit before you go will not necessarily prevent mountain sickness. Because of the possible progression to dangerous altitude illness, anyone who suddenly develops mountain sickness should never be left alone.
The alerting symptoms for the condition are: headaches, dizziness, fatigue, sleep disturbance, loss of appetite, nausea and vomiting.
If these symptoms occur, usually within six to 12 hours after arriving at high altitude, the ascent should stop. If there is no improvement after a rest, then it's time to return to a lower altitude where the symptoms should ease after one to three days.
