Working in a hospital emergency ward is a tough occupation at any time. Imagine, though, doing it 30,000 feet up in the air, over a war zone.
This was the everyday reality depicted in The Air Hospital, an extraordinary documentary about extraordinary people: the doctors, nurses and pilots who undertake medical rescue missions aboard the RAF's gigantic C-17 Globemaster aircraft.
The Globemaster was designed to carry troops into battle zones; now it's being used to bring injured soldiers out of Afghanistan and to conventional hospitals where they can receive the necessary treatment.
It's a massive beast. When all the lights in its belly are turned on, the 60-strong medical team -- ordinary doctors and nurses who would otherwise be working in private practice or NHS hospitals, but choose to do this for four months a year -- look as if they're inside an aircraft hangar, rather than an aircraft.
It takes them an hour to turn the plane into a fully-functioning ICU, before embarking on a seven or eight-hour flight, depending on conditions, from the RAF Brize Norton base to Afghanistan, and then back again.
The Globemaster flew 121 missions last year. Due to the worsening conflict in Afghanistan, this was more than twice as many as in 2008.
Paddy Wivell's rivetting film focused on two of them: firstly, to collect soldiers who'd been machine-gunned by an Afghan policeman they'd been mentoring, and later, to pick up a group that had been caught up in a firefight involving IEDs (improvised explosive devices).
The injuries caused by IEDs are particularly horrifying: arms, legs, even faces blown off.
The problem, said one young nurse, is you never know what's going to be inside them. Often it's shards of metal mixed with dog excrement, which is put in there to infect the wounds.
The psychological effects on less badly injured soldiers witnessing their pals being blown to pieces can be devastating. "I've never seen so much blood," said one traumatised young man, his barely shaved face a numb mask. "Lumps of blood, on the floor, on my legs."
The medical team work under incredible stress -- the roar of the engines alone makes communication next to impossible -- and so do the pilots.
The Globemaster usually lands under cover of darkness; on one mission here, however, it had to touch down on a short, narrow landing strip in broad daylight, making it a very large, very visible target.
The pilots have to execute what's known as an "assault landing": dropping 30,000 feet in just 90 seconds. A conventional passenger aircraft takes a half-hour to make the same descent.
Their default setting is humility. "We're just bus drivers," said a flight lieutenant called Niven Phoenix, which is a fitting name for a man who flies a big bird out of the ashes of death and destruction. "But sometimes the cargo is precious: the dead and the damaged."
Like all the best documentaries about war, The Air Hospital adopted a neutral tone -- show, don't proselytise. Yet, whatever your feelings about the rightness or wrongness of the war in Afghanistan, it was impossible not to feel humbled by the extraordinary courage shown here.
TOMORROW: Pat reviews Over the Rainbow (BBC1), as the wizard of the West End, Andrew Lloyd Webber, searches for his Dorothy
The Air Hospital ****