The terrain around them was uncompromising. The glacier they were on sat in a valley surrounded by high ridges. The peaks above them reached over 4,000 meters. The valley itself ran roughly east-west, deeper into the mountains in one direction and toward what might be lower ground in the other. They could not tell, from the valley floor, which direction that was. The snow was deep. The altitude meant that the air was thin enough to make physical exertion exhausting.
The temperature at that altitude in the Andes in October dropped well below freezing at night. The survivors had the clothes they had packed for a weekend trip to Santiago: sport coats, dress shoes, the kind of clothing that twenty-year-olds wear to a rugby match in a city. Some had brought warmer clothes; most had not. They slept in the fuselage, crowded together for warmth, with the openings at the front and back sealed as well as they could manage with luggage and debris.
Roberto Canessa and Gustavo Zerbino were both medical students. In the first hours after the crash, they triaged the injured as best they could with nothing more than torn clothing for bandages and intuitive knowledge of anatomy from their studies. Several survivors had serious injuries: broken bones, lacerations, internal injuries they could not fully assess. One survivor, Enrique Platero, had a metal rod from the aircraft embedded in his stomach; Canessa and Zerbino removed it. Their medical training was rudimentary at that stage — they were students, not doctors — but they were the closest thing the group had to medical personnel, and they applied what they knew.