Expedition doctor Monica Piris Chavarri spends her summers rock climbing in the Spanish Pyrenees, her winters skiing and ice climbing, and in between earns the money to fund her hobbies by working as a doctor in English emergency rooms. Born in Oxford to Spanish parents, she is fully bilingual.

In 2006, at the age of 31, she completed a diploma in mountain medicine. Her trip to Everest is the next step in her ambition to become a high-altitude specialist.

She plans to follow Russell to the North Col, where she can best monitor the team's health. "There's no reason for me to go to the summit," she says. "What use would I be if I were hypoxic? My responsibility is to make sure everyone remains fit and well."

Meet the doctor who rarely sees the inside of a hospital