Locum tenens are temporary doctors that work in a variety of assignments, usually on a temporary basis. We are currently hiring several since our group is short-staffed at the moment. These doctors tend to be hit-or-miss propositions. Many of them dropped out of medicine for awhile to have kids then came back, some work in other specialties and just do it to make extra money. The skill level is also very fluctuant. While we don't hire residents to work for us, some of the ones I've seen might have needed an extra year or two in training before they were released upon the world.
Locums: "Yeah, I admitted one last night. They have a fever, an infiltrate on chest x-ray and an elevated white blood cell count."
Me: "So they have a pneumonia?"
Locums: "Oh, umm...yeah, I guess they do."