Mont Blanc : Altitude Sickness - Is acclimatisation really necessary?

At 4810m there is approximately 30% less oxygen per breath than at sea level. That means that if you are unacclimatised, your body will struggle to cope and serious sickness may result. Acclimatisation not only reduces the chance of sickness, but allows you to travel much faster and enjoy the ascent much more.

What are the symptoms of Altitude Sickness?
In mild AMS (Acute Mountain Sickness), the main symptoms are headaches and nausea. Vomiting is a more serious indicator that you are not acclimatised. In the event of any Altitude related illness it is very important that you should not ascend any further as you are likely to become even more ill and may become completely incapacitated. Drugs such as Diamox (Acetozolamide) should not be used as an alternative to correct acclimatisation.