Stuart's vision blurred and dimmed, the room began to spin, he gasped for air in an attempt to fill his lungs with as much oxygen as possible given the elevation. His body had gone into autopilot, thrusting again and again in an animalistic fashion. Stuart finally climaxed and immediately after his body weakened and we both collapse on the bed. Earlier that day we had woken up at 800m (2,700ft) of elevation, we'd ended the day at 4200m (nearly 14,000ft) and it was our first experience at any substantial height. Lesson learnt; when you reach elevation for the first time, keep your sexual activity tame.