More than 100 people have died across the mountains this season so far, according to the European Avalanche Warning Services – a ballpark figure not seen for eight years. "As with all around the world, the climate is changing," says Frédéric Bonnevie, our guide and a mountain patroller for 32 years. If you don't have one, the rescue operation can take longer, requiring dozens of people and more equipment, and the survival rate drops to 20%. "Most of the time when we're coming, it can be too late," says Pierre Boulonnais, who has patrolled the slopes of Val Thorens for 17 years. "If you are trapped under just 50cm of snow of this density, you already have more than a quarter of a tonne on top of you," explains Bornet. Out of the millions of annual visitors to these resorts, the British make up a quarter, and for those disembarking the ski lift at an altitude of 2,800m (9,200ft), recent events seem at the front of their mind.