At a converted movie studio amputee actors prepare army medics for the shock and gore of combat wounds, while at a base in East Africa diarrhoea threatens national security. Beyond weapons and strategy, this is about the other side of war – how scientists protect soldiers from panic, exhaustion, heat and noise.

Setting about her task with infectious enthusiasm, the incomparable Mary Roach sniffs archival World War II stink bombs, tests earplugs in a simulated war zone with the Marine Corps and burns the midnight oil with the sleep-deprived crew of a nuclear submarine. Speaking to the scientists and the soldiers, she learns about everything from life-changing medical procedures such as testicular transplants to more esoteric innovations like firing dead chickens at fighter jets. Engrossing, insightful and laugh-out-loud funny, Grunt is an irresistible ride to the wilder shores of modern military life.