Visible crew/equipment: As Hawkeye walks over to the Colonel, there appears to be a lighting rig, or a reflector, over the Colonel's cot in the upper left of the shot. (00:20:35)
Visible crew/equipment: As Hawkeye is first approaching Danker during the triage scene, a boom mic can be seen at the top of the screen.
Answer: Even an Army field hospital would have SOME weapons for self-defense if the enemy attacked. What's meant is that it's not a combat outfit, and therefore wouldn't have enough weapons to actually attack anyone. (It's also mentioned a few times that the Officer of the Watch is supposed to carry a pistol at all times, but Hawkeye refuses to do it when he's in charge and Colonels Blake and Potter don't enforce the rule).
Captain Defenestrator