Sleeping at altitude

Most guests who arrive at Azure Skies Resort have crossed at least one time zone, driven over two mountain passes and climbed 1,400 vertical metres since breakfast. Then they lie down in a very quiet room at 1,815 m and expect to sleep as they do at home. Some do. Many do not, and they are surprised, and sometimes a little alarmed. This article is what I tell them at the first consultation, written down so that you can read it before you arrive.

What the first two nights feel like

At 1,815 m each breath holds about 20 % less oxygen than at sea level. Your body notices within hours. Breathing becomes slightly deeper and faster, even while you sleep, and a small proportion of guests develop a rhythm called periodic breathing: a run of deeper breaths, a pause, then a sigh that wakes them briefly. Sleep becomes lighter, with less deep slow-wave sleep and more short awakenings. On the wearable data we collect for the sleep assessment, the first night at Azure Skies typically shows sleep efficiency five to eight percentage points below a guest's usual figure. Many guests also report vivid dreams, a dry mouth, and waking around 03:00 with a clear head and no idea why.

None of this is an illness. It is acclimatisation, and it is the same process every mountain guide in the Engadin went through as a child. What matters is that you know it is coming, so that a restless first night does not become a worried second one.

What we do about it

The Azure Skies schedule is altitude-adapted, which means the first two days of every programme are deliberately lighter. Movement is a walk along the lake, not a climb. Treatments are warming rather than stimulating. We ask you to drink about a litre more water a day than you would at home, because the dry mountain air and the faster breathing both cost you fluid, and mild dehydration makes altitude sleep worse. We serve no alcohol on the first night, even to guests who are not on a programme; it is on the menu from the second evening, and by then most guests do not want it. Alcohol suppresses the breathing reflex you are relying on and fragments sleep on its own account; at altitude the two effects add up.

Bedrooms are kept at 18 °C by default, which is cooler than most guests expect and warmer than most guests end up choosing. Blackout is complete. There is no screen in the room unless you ask for one. Before bed we teach a short breathing sequence – six slow breaths a minute for five minutes – which tends to lower the heart rate and can ease the tendency to periodic breathing. It is not a ritual for its own sake; it helps, and you can take it home.

The first night belongs to the mountain. From the third, it belongs to you.

When to talk to a physician first

For most healthy adults 1,815 m is a moderate altitude that needs no medical preparation. There are exceptions, and I would rather hear from you before you book than at the front desk. If you have a heart condition, chronic lung disease, sleep apnoea treated with a device, or a history of altitude sickness, write to us; our physicians review the notes before arrival and may suggest a lighter first week, a different house or, occasionally, that you choose Aurora Bliss at sea level instead. We do not accept guests in the third trimester of pregnancy at Azure Skies, and we ask expectant mothers earlier in pregnancy to bring a letter from their obstetrician. Children are welcome from 12 years; they acclimatise faster than their parents and rarely notice anything at all.

What improves by night three

By the third night the picture usually reverses. Breathing has settled, the kidneys have adjusted the blood's chemistry, and many guests fall asleep faster and stay asleep longer than they do at home. Deep sleep returns, and it is often deeper than at sea level: the combination of cool air, complete darkness, silence and a day spent outdoors is hard to reproduce in a city. On the assessment data, guests who stay seven nights leave with sleep efficiency on average nine percentage points above their first-night figure. We measured that on 312 programme guests in 2025 – a fictional statistic for this demonstration site, but the shape of the curve is real and every sleep physician who works at altitude will recognise it.

What we cannot promise is that the improvement travels home unchanged. What does travel is the habit: a cool dark room, a fixed lights-out, no alcohol close to bedtime, five minutes of slow breathing. Guests who keep those four things tend to keep most of the gain. That is why the Zayana Reset programme ends with a written plan and a 30-day follow-up call, and it is why I am still a physician rather than a spa director.