Surgery Under Fire

Somebody is seriously injured, and in need of some After-Action Patchup. Unfortunately, the action isn't over, so whatever fixing up needs to happen is going to have to be done while the battle is still raging. If they're lucky, there'll be medical bay nearby they can be treated at, otherwise they'll have to make do with The Medic sprinting out onto the battlefield with a quick cry of "Cover Me!". In the worst case scenario, there's no-one else around, and the wounded soldier is just going to have to make to with some Self-Stitching.

This is a great way of rising the stakes in an already tense battle scene, as it adds just one more thing for the heroes to worry about. May well lead to, or be the result of, a Shoot the Medic First situation.

Fan Works

 * Naturally M*A*S*H had multiple instances of this. In numerous episodes members of the 4077th were required to perform surgery at the front or under fire, including an episode where the entire camp was being shelled by friendly fire, and another where Father Mulcahy had to perform a tracheotomy on a wounded soldier in the back of a parked jeep at the side of a road while North Korean shells were falling all around him.

Film

 * In Saving Private Ryan, in a notable scene at the beginning, a medic is trying to stabilize a fallen soldier on Omaha Beach, seemingly without concern for the sheer number of bullets flying around.
 * The backdrop for the big standoff at the end of Avengers: Infinity War is the Wakandan forces attempting to hold off Thanos, while Shuri performs what is essentially brain surgery on Vision.

Music

 * The Alestorm song Wooden Leg tells of a pirate who has his leg blown off in navel combat, gets a wooden leg fitted below deck, and hops straight back into the fray.

Video Games

 * This is a fairly standard affair in multiplayer games, where other players can rush to the side of downed allies in order to revive them.