Building a climbers' shelter 3000 m up a French mountain is a job for high-fliers only – and even then it can end up being a real cliffhanger
You've heard of extreme sports; this is extreme building. Under normal circumstances, putting up a hostel that sleeps 70 people in basic conditions would be pretty straightforward – but try doing it on a mountainside 3167 m above sea level where daytime temperatures barely rise above freezing – in July.

That's the challenge facing workers on Tête Rousse, a climbers' lodge that serves as the first staging post en route to the summit of Mont Blanc, Europe's highest mountain. The €1.6m (£1.1m) project by architect Gaston Muller is the first in a series of shelters planned by the French Alpine Club, which has 7000 beds on its estate, at the disposal of its 90,000 members.

"Our goal is to make our national heritage available to as many people as possible," says club president Bernard Mudry. "Some of our shelters accommodate ramblers who stay for several days; others are for climbers who stop there for one night."

Tête Rousse is one of the latter. Its inhospitable location means construction work can go ahead only on four months a year.

Last year, 800 helicopter trips were needed to ferry in the materials for the basic structure. Twenty intrepid carpenters and masons worked on the site. The stainless steel roof is curved on the valley-facing side to resist the wind, whereas the rear roof is flat and downward-sloping to allow melting snow to trickle away.

This summer's programme includes fitting photovoltaic panels on the roof to provide electricity. Running water, however, is a luxury that the shelter's visitors will have to do without when it opens in 2004.

However, a work of warning for anyone contemplating an ascent. "Seventy per cent of the people who set off to climb Mont Blanc are not fit enough, and they often stop, exhausted, before they reach the summit," says Jean-Bernard Rhodet, who has been running the old shelter for 20 years.

So if you're thinking of tackling Mont Blanc, train like mad, pace yourself and plan meticulously. Otherwise, a night in Tête Rousse could be the closest you come to the top of the mountain.