600 eco-conscious volunteers turned up under blue skies near the foot of the Aletsch glacier, a protected UNESCO World Heritage site.

Environmental group Greenpeace commissioned the photo shoot from world renowned photographer Spencer Tunick.

"It's relatively chilly but that doesn't seem to be disturbing them." told Nicolas de Roten of Greenpeace Switzerland.

Tunick split the men and women into two groups of about 300 for separate shots on or around the lower end of the spectacular 23 kilometre long (14 miles) sweeping ice floe, at an altitude of about 2,300 metres (7545 feet).

Dressed in hiking gear, they stripped for minutes at a time, watched at a distance by a clump of media photographers and journalists.

While cooler than the valley below, temperatures were well above freezing -- about 10 to 15 degrees Celsius (50 to 60 Fahrenheit).

The campaign is aimed at drawing attention to melting Alpine glaciers, one clear sign of global warming and of man-made climate change, according to the group.

Greenpeace says the human body is as fragile as glaciers like the Aletsch in southern Switzerland and the world's environment. The glacier itself is now shrinking by about 100 metres (110 yards) a year.

The group hopes its billboard and poster campaign showing people exposed to the cold will send a shiver down the spines of public opinion and politicians, and convince them to do more to tackle pollution and climate change.

http://www.greenpeace.org/international/