Wickwire reached the summit of K2 with Louis Reichardt on September 6, 1978. The pair took photos on the summit, and then Reichardt started his descent immediately because he had made the climb without supplemental oxygen. Wickwire lingered a little longer, with the intention of catching up. Upon his descent it was beginning to get dark however, and Wickwire did not have a headlamp. Concerned about being able to move safely in the dark, he decided to spend the night where he was, which was below the summit but above . Wickwire had done bivouacs before and knew he just needed to gut it out until daylight, which was risky because of the thin air and severe cold. Risks include: hypoxia, hypothermia, frostbite, cerebral edema, pulmonary edema, and falling.