A collection of powerful images from humanitarian missions around the world are currently on show in London as part of the World Extreme Medicine Expo. The photographs highlight some of the complex and challenging operating environments in which (often voluntary) staff risk their lives to save those of others. For a snapshot gallery, see: http://www.theguardian.com/global-development/gallery/2015/oct/26/extreme-medicine-msf-daredevil-doctors-humanitarian-frontline.
Photo credit: John Moore/Getty Images
Photo credit: Matthias Steinbach/MSF