You’ve surely heard of Doctors Without Borders — those physicians who venture into war zones and disaster areas to supply emergency medical relief.

But seeing the documentary “Living in Emergency” makes the actual hands-on work of MSF (the initials from the original French name of the group, Medicins Sans Frontieres) much more understandable. If anything, the disaster areas are even worse than you might have imagined.

This film was mostly shot during a couple of MSF missions in 2005. One goes into the heart of darkness that is the Congo, another into Liberia in the aftermath of a horrible civil war.

What we see are doctors improvising in dire situations, sometimes with patients injured by violence, other times with people who simply have had no health care for many years. There’s no discreet cutting away from surgery or bullet wounds, so be advised.

We focus on a few people in particular, and watch their progress. On the one hand, there’s an Australian doctor, Chris Brasher, who’s been in the MSF ranks for nine years; like a character out of “MASH,” he’s developed a thick skin and a way to keep his equilibrium in the midst of war zones.

At the other end is another Aussie, Davinder Gill, who is on his first mission at age 28. Exiled to a far-off Liberia outpost, the high-strung Dr. Gill seems on the verge of losing it, overwhelmed by his frustration at bureaucratic problems and lack of necessary supplies.

There’s also a Tennessee surgeon, Tom Krueger, who left his lucrative 20-year practice so he could do something with MSF. He seems to be adapting the right philosophical attitude to weather the vagaries of working in a constant state of crisis.

Director Mark Hopkins’ emphasis in the movie can be questioned: By focusing on the doctors, the film continues a long tradition of telling stories about the visitors to Third World countries, not about the people who live in those places.

Still, this portrait is vivid. So vivid it is difficult to watch at times, and not just because of the explicit surgical gore.

Among the heart-rending scenes is a girl who recovers from surgery on her broken arm only to remember that her parents have been killed in an attack. As a nurse says, “Now it is not just the pain, it is the sorrow.”

This film will certainly make you think more about the ground-zero world of disaster areas. As one observer puts it, there’s a sameness to the temporary missions MSF undertakes: Wherever you go, you see “civilians who are terrified, and some people who enjoy killing other people.” Which is why the group is needed, unfortunately.