There was a chapter in Stephen Ambrose's Citizen Soldiers where a captured medic ended up working with the German medical unit, and they taught each other different medical techniques. Its important to remember that Allied medical units had access to penecillin, which the Germans didnt have

Well normal etiquette when confronted by a marked combat medic is not to shoot them or harass them. But sometimes that was not always the case. The Germans tended to follow the Geneva conventions rules on protected persons. The Fog of war would get in the way, a mortar round into a foxhole does not follow the laws of war, soldiers die in battle and combat medics fell victims. If a medic was captured, well it depends on what uniform they had on. Lets say its a US combat medic, captured in the field. First off the opposing forces would check him for weapons, intelligence... They would know he was the medic because of the red cross he had on his arm and or helmet. they might take his medical supplies and give it to their own medics or they could get the US medic to aid the wounded, on both sides of course. Once the US medic was taken off the front lines, he would be transported to a POW collection point, the Geneva Convention says that the capturing forces must remove POW as quickly and safety from the combat zone, if possible. So there's the US medic with other US/Allied soldiers. He would be treated just like any other POW, sorted out by officer/enlisted, branch of service. Once he arrived at a POW camp, they would be registered/documented and given a job assignment, most likely in the infirmary/sick bay. My papa was a US Medic during WW2, he worked in a POW camp down in Carolina and Georgia, he was an enlisted man and ran the German hospital unit within the POW camp, he was in charge of a team that was staffed by German Doctors and field medics, mainly from the Afrika Korps. here are some good WW2 medic sites if your interested http://www.mtaofnj.org/content/WWII%20Combat%20Medic%20-%20Dave%20Steinert/index.htm#World%20War%20II%20and%20the%20Combat%20Medic

http://www.med-dept.com/articles/identification-of-medical-personnel-vehicles-and-installations/