Popular Mobilization Forces (PMF) fires towards Islamic State militants during a battle with Islamic State militants, west of Mosul, Iraq February 22, 2017. (Photo by Reuters/Stringer)
Members of the Royal Navy respond to a simulated fire in a Vanguard-class submarine control room training facility at Clyde naval base in Faslane, Scotland on January 21, 2016. (Photo by Photograph: Danny Lawson/PA Wire)