The first 15 minutes

For a long time, a simple rule applied: more than 90 per cent of buried people survive the first 15 minutes. It comes from an analysis of 422 completely buried people in Switzerland, published by the team around Markus Falk and Hermann Brugger in the journal Nature in 1994. The rule is not wrong. The curve simply drops earlier today.

A team led by emergency physician Simon Rauch, which also included Brugger and Falk, analysed Swiss data from 40 winters in 2024: 1,643 people whose heads and chests were under the snow. After ten minutes under the snow, the probability of survival was 91 per cent, after 15 minutes 76 per cent and after 30 minutes 31 per cent. The bend in the curve therefore comes after just ten minutes, not only after 15. The reason has not been established with certainty. The authors consider earlier suffocation more likely than an increase in injuries.

An overview by the International Commission for Alpine Rescue of 120 studies shows what buried people die from: most suffocate, in 65 to 100 per cent of cases depending on the study. Injuries follow at 5 to 29 per cent, while hypothermia is rarely the cause, at zero to four per cent. That is why the people already there matter. If the group digs, the person is free after an average of ten minutes. The rescue service takes an average of 90 because it first has to be alerted and travel to the site. Those rescued by their own group survived about three times as often.

Depth also matters. An analysis from Austria and Switzerland in 2016 shows that the duration and depth of burial act independently of each other, and that an air pocket in front of the face improves the chances, especially after 15 minutes. In Switzerland, buried people were at an average depth of 80 centimetres.

Searching with an avalanche transceiver, or LVS for short, has four phases. The Ortovox Safety Academy compares them with an aircraft’s landing approach: the closer you get to the target, the slower and more precise you become.

The probe tells you exactly where the person is and how deep. Start at the marked point and probe outwards in a spiral, about every 20 centimetres. The angle is important: at right angles to the snow surface, so on a slope not vertically downwards, and the same for every probe. If the angle changes, gaps remain at depth.

Probe to at least one and a half times the depth last shown by the device. A body feels soft and springy, a stone hard. If you hit something, leave the probe in place; it shows the way when digging. Do not step on the snow around the probe, otherwise you may compress an air pocket. The probe must also be long enough: the Swiss avalanche-prevention training team requires at least 240 centimetres.

Digging out takes by far the most time. If everyone simply starts digging, they get in each other’s way. Manuel Genswein and Ragnhild Eide therefore described and tested the V-shaped snow conveyor belt in field trials. Groups without this system took 42 per cent longer at a depth of one metre and more than twice as long at two metres.

If you are alone, you also start downhill of the probe. The DAV recommends starting about one to one and a half times as far away as the probe is deep.

As soon as the face is clear, the key question is whether the person can breathe. The recommendations of the International Commission for Alpine Rescue (ICAR MedCom, as of 2023) are as follows:

If there are several of you, one person calls and at least one starts searching immediately. The person on the phone should stay at least 25 metres away from the searchers so that the mobile phone does not interfere with the avalanche transceivers. If you are alone or have no signal, search comes first. There is no fixed rule on whether someone alone should call or search first. We do it this way: search first, then make the emergency call as soon as it is possible without losing time.

Five details help on the phone: what happened, where it happened, preferably with coordinates, how many people are buried, who is calling and when it happened.

A transceiver, probe and shovel belong together. A device without a probe finds the person, but not quickly enough. A probe without a shovel shows where they are, but not how to get them out. All three only help if everyone carries them. Anyone travelling as the only person without a device can neither search for anyone nor be found themselves. Keep the probe and shovel in your backpack, within easy reach; the backpack guide helps you find one that fits.

An avalanche airbag acts one step earlier: it can prevent you from being completely buried in the first place. An analysis of accidents from seven countries found that mortality fell from 22 to 11 per cent when an airbag was deployed. However, one in five airbags was not deployed, usually because of an operating error. Anyone who is buried despite using one needs the same search as everyone else.

The search itself is quick to learn. It becomes difficult under stress, with cold hands and someone you know somewhere under the snow. That is why professionals practise regularly, and not just with the device. The DAV advises practising probing and digging just as intensively as the transceiver search. Every tour should also start with a group check: every device transmits and every device receives. And before you set off, check the regional avalanche bulletin and the snow and wind on the weather radar.

No article or screen exercise replaces a course in the field. The Ortovox Safety Academy offers avalanche courses with certified mountain schools in small groups, as well as the free LAB Snow learning platform with a dedicated chapter on companion rescue. Courses are also available from the German Alpine Club, the Austrian Alpine Club and the Swiss Alpine Club.

Next, see Transceiver, probe, shovel and the finder Which avalanche transceiver suits you?. Everything from Ortovox in our range is in Experience Ortovox.