Altitude and safety on an Everest helicopter tour

What health authorities say about altitude

The points below are general information from the CDC Yellow Book and the NHS travel health service fitfortravel. They are not medical advice for your trip.

• The CDC counts any traveller who is not acclimatised and goes to a sleeping altitude of 2,450 m or more as at risk of altitude illness.
• The NHS service writes: “The higher and faster the ascent, the more likely that AMS will occur.” AMS is acute mountain sickness.
• Symptoms the NHS lists include headache, dizziness, nausea or vomiting and breathlessness. The CDC calls headache the cardinal symptom.
• The CDC notes that day trips to high altitude with a return to lower altitude in the evening are much less stressful on the body than sleeping high.
• The NHS service advises travellers with certain conditions, among them heart and lung conditions and pregnancy, to seek expert medical advice. The CDC advises travellers with conditions such as coronary artery disease or chronic lung disease to see a physician familiar with high-altitude medicine before they go.

What the listings say

One private listing says its tour is not suitable for pregnant women and people with heart problems, vertigo or respiratory issues. Several listings name oxygen on board: one lists an oxygen tank, a first-aid kit and an oximeter to check pulse, oxygen saturation and heart rate; one names flight insurance and emergency oxygen; the private group tours name an oxygen cylinder for emergencies or oxygen support. The flights below are the ones whose listing mentions oxygen. For the others, ask the operator what is carried on board.

Weight limits per passenger

The shared listings set a limit per passenger between 198 lbs (90 kg) and 265 lbs (120 kg), depending on the flight; the private group tours do not state one. The reason is thin air: a helicopter operator in Kathmandu gives a total load of 500 kg from Kathmandu to Lukla and 250 kg from Lukla up to Kala Patthar or Base Camp. Weigh yourself in the clothes you will fly in and tell the operator your weight when you book. The limits of each flight are in the fact sheet on the comparison page.

Time at altitude

The listings here do not state how long the helicopter stays at each stop. One Kathmandu operator gives about 10 to 20 minutes at Kala Patthar or Base Camp, and writes that such brief landings may cause mild altitude effects. If you would rather not go that high, choose a flight that stops lower, at Pheriche or at Syangboche below Hotel Everest View, or the mountain flight by plane, which does not land. Landing points per flight and helicopter or plane compared.