Packing and pacing for high places

Many of the world’s most memorable places sit high above sea level: Cusco at about 3,400 metres, La Paz between roughly 3,200 and 4,100, and the Alpine and Patagonian trails that climb well above the treeline. Altitude can cause headaches, breathlessness, poor sleep and nausea, and in rare cases dangerous illness. The best protection is a slow ascent.

Health agencies such as the UK’s TravelHealthPro and the US CDC advise avoiding large jumps in sleeping altitude, taking rest days, and drinking water. The CDC notes that in places such as Cusco and La Paz, some travellers sleep at a lower altitude for a night or two before going up. If you fly directly into a high airport, plan a gentle first day. Speak to a doctor before travelling if you have heart, lung or other health conditions, or are pregnant, and ask about medication for altitude.

For your bag, think layers. Days can be hot and nights near freezing. Pack a base layer, an insulating mid layer and a windproof, waterproof shell, plus a warm hat and gloves. Sun protection matters more than people expect, because ultraviolet radiation is stronger at altitude. Bring sunglasses, a hat and high-factor sunscreen.

Footwear should be broken in. Sturdy hiking boots with ankle support suit rocky trails; trekking poles help on long descents. A small daypack with water, snacks, a first-aid kit and a headtorch covers most day hikes.

Finally, listen to your body. A mild headache is common; worsening symptoms, confusion, breathlessness at rest or loss of coordination are reasons to descend and seek medical help. No summit or viewpoint is worth ignoring those signs.