The sleeping bag was assembled from materials available in the aircraft: the aircraft’s insulating material, seat covers, nylon cord from luggage, and other fabric. The construction was painstaking and required many hours of work. The result was a sleeping bag that could allow two people to sleep in temperatures that would otherwise have been fatal. Without it, the planned expedition to the west — which would require sleeping in the open on the glacier — would have been impossible.
This construction project — practical, collaborative, focused on a specific survival goal — also served a psychological function. It gave the group something concrete to work on. The survivors had been in the mountains for over a month. Many of them were physically deteriorating from malnutrition and cold. Having a focused task with a clear outcome was important for morale.
The expedition plan identified three people to make the westward crossing of the ridge: Nando Parrado, Roberto Canessa, and Antonio “Tintin” Vizintín. The choice was based on physical condition and psychological readiness. Parrado had emerged in the weeks after the avalanche as one of the strongest and most determined members of the group. His grief over his mother and sister, combined with the experience of having been left for dead by the official search, had produced in him a focused intensity that all accounts describe. He was not willing to die in the mountains. He was going west.
Canessa was physically strong and had the medical knowledge to monitor himself and the others. He had also been among the most active expeditionaries during the preliminary scouting missions. Vizintín was athletic and had performed well on the earlier expeditions.