The heights of folly

My house jobs had finished, and I had just arrived in Huaraz, northern Peru, for a trek around Mount Huascaran with Andy, my fellow senior house officer and flatmate from medical school.

After 72 hours of acclimatisation at an altitude of 3500 m, we set off for the five day adventure. As dawn broke, we started to ascend, my only symptom being a mild headache. After four hours of climbing the near vertical mountain footpath, the headache had matured into a persistent thump with each heartbeat. Further water and painkillers weren't having much effect. My pace had slowed, much to my annoyance, and we were still some distance from the first pass at a height of 4900 m. My shortness of breath …