One hundred million Americans will use an emergency room this year. From stitches to gunshot wounds, the flu to heart attacks, the men and women who work in these pressure-packed places are at the front line of the battle against death. This episode goes inside a busy emergency room to see how the paramedics, doctors and nurses work together. As the cameras roll, these real-life heroes fight a variety of ailments and injuries, constantly adjusting to the flow of new patients and swiftly changing situations. Trace the development of the machines that have transformed the face of emergency medicine, from the ambulance to the electrocardiograph, and see how medical techniques have evolved over the years. And find out why Mt. Everest may hold the key to the future of emergency medicine.