Acclimatisation, explained without the jargon

Above about 2,500 metres every breath carries less oxygen. Your body adapts, but it needs time: more red blood cells, faster breathing, changes in how your blood carries oxygen. Acclimatisation is simply giving it that time.

Walk high, sleep low

On rest days we hike a few hundred metres above camp and come back down to sleep. The climb tells your body to adapt; the lower bed lets it recover. It is the single most useful habit at altitude.

Three symptoms to take seriously

• A headache that does not ease with water and paracetamol
• Breathlessness while resting
• Confusion, clumsiness or unusual tiredness

Any of these means stop climbing and tell your guide. Going down a few hundred metres fixes most problems quickly. Our guides carry oximeters and check everyone each evening.