Summary of Mary Roach's Grunt examines technological and medical research in the military. Each chapter focuses on a different topic—for example, diarrhea among soldiers—and then presents historical background, interviews with scientists and affected military personnel, and possible solutions to the problem.

Military research in both news accounts and films is usually presented as a matter of technology and combat equipment, such as faster airplanes, better bombs, and deadlier weapons. Much military research, however, is devoted to finding ways to protect soldiers or to help them cope in the aftermath of injury. For instance, researchers work constantly to develop clothing fabrics that will keep soldiers cool while still providing camouflage—a difficult task because the black in camouflage absorbs heat. Doctors and surgeons constantly develop new ways to address injuries from bombs and gunshots. They have made advances in reconstructive genital surgery and even some strides towards successful penis transplants...