The Welshmen saving soldiers on Afghanistan's frontline
All this week our correspondent Colette Hume has been reporting from Afghanistan.
In her fourth report she meets the Welshmen whose job it is to rescue injured soldiers and bring them to the hospital - often in the face of huge dangers.
A casualty reaches the hospital at Camp Bastion but the process of saving a soldier's life begins long before he reaches the emergency department . . .
When soldiers are injured here in Afghanistan many of them are rescued by helicopter.
Every day teams of doctors and nurses fly into danger, often under Taliban attack.
I met William Thomas from Swansea who is in the RAF. It's his job to protect those helicopters and the medical team.
He is a quiet, modest 23-year-old who does one of the most dangerous jobs in the armed forces.
"Soon as you land you concentrate on protecting everyone to the best of your ability," he said.
"When you do get the casualty onboard you try to help as much as you can, that can be dressing, holding the fluid bags."
He does an incredibly dangerous job, so are there times when he is frightened?
"It is frightening, but it's true your training just kicks in and you get on with it, you're just thinking about the job that you have to do, and getting the casualty to safety."
He says his family in Swansea worries about him and know exactly how dangerous his job really is: "I'm an open person. I tell them everything so that they don't worry."
The decision to send Tommo - as he's known - into danger is made here at the hospital by two men from Cardiff, Lt Greg Conway and Sgt Major Ceri Caesar.
They treat all injured casualties - soldiers, civilians and even insurgents.
They co-ordinate the rescue missions.
Lt Conway told me: "The first hour is absolutely imperative to get the person off the ground and straight in, especially when we're looking at Kat Alphas from gunshot wounds and traumatic amputations from IEDs.
"They call it the golden hour for a very good reason indeed."
The staff at this hospital know the Taliban are targeting their colleagues on the rescue helicopters yet injured insurgents receive exactly the same treatment as coalition forces.
"It's not my job to play God, we treat everyone," says Sgt Major Caesar.
But they both know the huge risks they are asking the rescue teams to take every time they send them out.
Sgt Major Caesar told me: "I have been a professional soldier for 31 years.
"Some of the things I see out here I've never seen before in my professional career but to know that we are making a difference . . . certainly the guys in that Landrover are making a hell of a difference.
"Having to task them every day sending them into really, really bad places knowing that the insurgents are trying to take them out, they really are.
"They are constantly trying. They know how we work and they are evolving their techniques to take them down."
And you send them out into that, I asked.
"Yes, very much so. It's not an easy task, but if you don't do it people can and will die."