Following the fatal avalanche in the French Alpine resort of Tignes, in which at least four people have died, the Foreign Office has issued an emergency number: "If you’re concerned about family members, you can call the local town hall on +33 4 79 40 09 91 for information (English available)."

The latest FCO bulletin adds: "If you’re in the area, you should follow the advice of the local authorities."

The Monday morning forecast for Tignes from the Ski Club of Great Britain looked benign: “A dusting of new snow. Temperatures will be below freezing (max -2°C on Wed morning, min -5°C on Mon afternoon). Wind will be generally light.”

But the avalanche warning level from MeteoAlarm, the Europe-wide warning site for extreme weather, was yellow, meaning: “The weather is potentially dangerous … be attentive if you intend to practice activities exposed to meteorological risks.”

In an average winter, around 25-30 people die in France because of avalanches, with February usually the peak month for fatalities.

Typically the victims are skiing or snowboarding off-piste, or ski touring — participating in back-country expeditions that include climbing as well as descending.

The Foreign Office warns British skiers in France: “Check weather forecasts and conditions and make sure you’re properly equipped. Don’t undertake any activity alone, and consider hiring a guide for expert advice.

“Observe all warnings regarding avalanches and where appropriate consider carrying avalanche search equipment.”

Avalanche airbags, typically costing £600 or more, can improve the chances of survival. Off-piste skiers and snowboarders, and ski tourists, are also recommended to carry an avalanche transceiver, which should be switched on whenever they are skiing. The devices cost around £150.

The most dangerous version of the phenomenon is a “slab avalanche”, in which a plate of snow about one to three feet deep slides rapidly down the mountain, accelerating to around 80mph.

The US National Avalanche Center in Idaho says: “The rapid addition of the weight of a person can easily initiate the fracture on a slope that would not have avalanched otherwise. A slope can lay in waiting like a giant booby trap — just waiting for the right person to come along.”

It publishes an Avalanche Danger Scale, which skiers and snowboarders can access for individual resorts.

Last month a hotel in central Italy was buried by a massive avalanche triggered by an earthquake.