How do you push some of the world's best climbers to their breaking points? Add ice to an already burly crack climb. The conditions might have seem perfect as our four climbers arrive at the summit of Chamonix's Aiguille du Midi, but on the rock, the reality is very different. Melting ice has trickled its way down the classic crack climb 'Enfer du Decor' (7b+), transforming the already stout challenge into a cold, slippery nightmare.