A vest designed at Georgia Tech for the U. S. Navy could instantly tell medical personnel where a wound is. Woven through the vest is an optical fiber. Precisely timed light pulses are launched into the fiber and strike a photodetector at the other end. A bullet would break the fiber, interrupting the light signal and triggering a transmitter to summon help. Light is reflected by the broken fiber to the source; timing the return of the optical echo permits the system to compute the location of the break and thus of the injury. Sensors woven into the garment can continuously monitor vital signs and feed the information to a portable computer worn on the hip-a kind of high-tech dog tag. A fallen soldier’s position and physical status can be automatically transmitted to a triage unit. Such a garment could appeal to a broader class of potential users, including athletes in training.