Inventors and Their Inventions

Joe Carolan
Quick-Finders, a guidance system for rescue personnel
A reflective device engineered to pick up light from multiple angles, Quick-finders are affixed by a homeowner to the baseboards outside bedroom doors. That way, says Carolan, when a fire fighter is crawling through smoke "we can pick up the reflectivity and know where the bedroom is instead of going into the closet, the bathroom, or the kitchen." Carolan got his idea during a training drill. "We were crawling through a smoke-filled building looking for a child and we couldn't find the bedroom. And it was 2 feet in front of me. I figured out there had to be a better way. The a-ha moment came right then."

• 50 Best Inventions 2009