Doctors Without Borders/Médecins Sans Frontières (MSF) has developed a Mobile Unit Surgical Trailer (MUST) for use in the field. The idea of the MUST is to be more flexible, more hygienic, and quicker to implement in conflict and disaster zones around the world. It is comprised of a number of trailers that can be transported on trucks. The MUST has been used for the first time south of Mosul in Iraq where it allowed MSF teams to conduct lifesaving war trauma surgery in hygienic and temperature controlled conditions. The MUST is now being further optimized for use elsewhere in the world.