World War I marks the first time in American history that Army medical personnel were assigned to work directly in the field, alongside combat soldiers. In addition to administering first aid to wounded troops, these field medics also evacuated soldiers from the field. Sometimes this was accomplished with a pulley system in the trenches, but more often than not, it meant dragging their countrymen through acres of difficult terrain.
Once cleared from the field, the medics were greeted by any of up to 83 different kinds of ambulances -- from horse-drawn wagons to more modern jeep-like vehicles [source: History Channel]. Because World War I marked the first time gas had ever been used in combat (it was first employed by the Germans on April 22, 1915), special ambulances were devised that provided showers for soldiers to wash off contaminants and gas masks were distributed.
Although the work was bloody, muddy and backbreaking, medics did get some assistance in their fight to keep America's fighting forces alive. The Red Cross grew exponentially during the war, with membership numbers and local chapters skyrocketing. As a result, the organization recruited 20,000 registered nurses to work in military hospitals and ambulance companies [source: American Red Cross].
Military medical personnel also got a helping hand from science. Thanks to new technologies such as portable X-rays and the antiseptics and inoculations that grew out of modern germ theory, World War I was the first war in which disease didn't kill more men than battle injuries.
The body of medical knowledge had grown even more by World War II, and the widespread use of penicillin and antimalarials helped keep soldiers healthier than ever -- if not exactly out of harm's way. When soldiers were wounded, the first use of morphine in the field -- through self-contained needle delivery systems known as syrettes -- helped to ease their pain. All soldiers were also equipped with Carlisle Model enhanced first aid kits that contained, among other helpful gear, a bandage with long tails that could be quickly and easily tied around a wound.
Thanks to advancements like these, by the end of World War II, the odds of dying from combat-related injuries had dropped significantly to 30 percent.