What happens to Wickwire during the summit?

From the text:

Without a headlamp, he couldn't make the technical descent in the dark and Wickwire was forced to endure one of the highest bivouacs ever recorded. His oxygen ran out and he suffered severe frostbite, pneumonia, pleurisy, and a cluster of potentially fatal clots in his lungs. Reichardt and the rest of the team struggled to keep him alive with constant medical care, until Wickwire could be evacuated by helicopter to a hospital, then home to Seattle where he underwent major chest surgery to repair the clots.