(CNN) The feeling of being in over your head is something most people have encountered at some point.

You know that you are not equipped or trained to handle the situation but that you can't stop it. You simply have to take it on.

For one group of surgeons sitting in a room in Turkey, their experiences with that feeling are far and beyond those of almost anyone else.

These 32 surgeons have crossed the border from Syria and in five days will be returning there to continue treating the myriad patients coming through their hospitals, each with extensive injuries the doctors will have never seen before.

Through no choice of their own, they are now war surgeons -- and they have had to be for five years.

"War surgery's an art of its own, to be really honest," said British surgeon Dr. David Nott, who has more than 23 years of experience on the front lines of war zones and shares his knowledge through bespoke courses . "People are dealing with mass casualties on a daily basis and ... injuries which they would never have see anywhere else before."

Nott has brought this group of young surgeons to Gaziantep, Turkey, to impart his decades of knowledge over just a few days in a Hostile Environment Surgical Training Course. The goal is to make them ready for anything -- even if they don't know what they're doing.

David Nott works with surgeons in his course in Gaziantep, Turkey.

"Our course is basically about training them in dealing with some of the most horrendous injuries that they probably will see," Nott said, so that they can "offer the best surgical operations with the best results they can get."

When someone becomes a war surgeon, they inevitably require the skill set of multiple medical disciplines. "You have to deal with every region of the body," Nott said. "(And) you have to deal with the physiology of the patient, the problems with low blood pressure and not enough fluids going round."

Trauma textbooks are to be ignored to some extent, because no textbook can prepare doctors for the on-the-spot thinking they are going to need. It all comes down to skill.

But this training also includes knowing when to do nothing, because resources need to be preserved. And with fewer hospitals now available and fewer doctors within them, resources are scarcer than ever.

"They don't have a huge amount of blood or lots of equipment," he said. "So it's (also about) showing them the reasons why they probably shouldn't operate on some patients that come in."

'The worst thing'

One memory stays in Nott's mind, acting as a reminder of why he works in this field. It's a memory from Aleppo in 2014, of a family of six he was unable to help.

"There was a barrel bomb dropped on a family," he said. The father had died, but the mother brought her five children to the hospital. One of the children had also died but remained in her arms.

"She was screaming," Nott recalled. "She picked up one of the children who had died and couldn't believe that the child had died and was trying to give it some milk."

Nott soon met the remaining family members, each with extensive injuries: missing body parts or brains exposed due to something falling on their head. One of them, a boy about 4, had had his buttocks blown off.

"I went over to see him, knowing there that I couldn't do anything to help him," Nott said. "All I could do was just brush his hair, basically. That's all I could do."

David Nott still vividly remembers his worst experience in the field.

It was the worst scenario Nott had ever witnessed, despite encountering victims of multiple wars since his first entry into the field in Sarajevo in 1993 during the Balkans conflict. He's since worked in Afghanistan, Pakistan, Iraq, Yemen, Liberia and multiple other countries.

"We all have these memories ... that stick in our head," he said. These memories now spur him to continue helping others who regularly face similar horrors better handle such situations -- and be ready for them.

Being ready

Nott trains surgeons from both developing and developed countries to be prepared for the challenges awaiting them in a war zone, with one of his courses conducted through the Royal College of Surgeons in the UK.

"We have other courses that we train ... for people that are going out," he said.

The goal is still to fit his 20-plus years into just five days, with a focus on just how to provide emergency surgical care to populations faced with conflict or natural disasters, making triage decisions based on the available resources, working with cadavers to perform a range of surgical procedures and to manage obstetric and gynecological emergencies, including when -- and how -- to perform a caesarean section.

Nott admits to being a "completely different humanitarian surgeon" than he was when he began his endeavors.

"I understand what it's like to go to war. I understand what the injuries are, (and) I can understand the physiology," he said. "Although things may be happening around me, I'm concentrating on that patient."

Nott's courses and abilities are renowned in the field of humanitarian care, and nonprofits around the globe send their medics and surgeons to his courses.

"UK surgeons are usually highly specialized and so often do not practice these types of surgery in their everyday work," said Katie Gatward, a nurse and human resources officer for Medecins Sans Frontieres (Doctors Without Borders) in the UK, whose organization sends surgeons to train with Nott to better equip them for the austere settings where they may find themselves.

"They will need to be able to manage life-threatening emergencies that can happen during pregnancy or labor, care for burns, perform amputations as well as treat gunshot wounds and manage complex multiple trauma," she said.

But as much as specialized surgeons from around the world need to broaden their skills, many experts acknowledge that the people born and bred in war zones, who are unable to leave, are the ones in dire need of this training.

The ones who stayed

"Not many doctors have stayed in Syria," said Dr. Karl Blanchet, co-director of the health in humanitarian crises center at the London School of Hygiene and Tropical Medicine. "But you have medical students who have not finished their training ... and they have to do surgery ... and acts that are not part of their skills of specialty."

Blanchet adds that the current situation in Syria has forced many medical schools and hospitals to close, leaving students in need of whatever external training they can get. He further added that although war surgery was given attention in terms of materials and training during the Balkans conflict, the field was neglected after that period due to other issues needing attention, making Nott's work more essential than ever.

"The needs changed over time, but Syria has brought this field back to the forefront," Blanchet said, highlighting the numbers of bombings and targeting of civilians being seen right now. "Since the war in Yugoslavia, we haven't seen that."

Nott agrees that the extensiveness of the trauma today is unlike anything he's seen before.

"Syria itself is really, I would say, at the pinnacle of the worst possible humanitarian crisis, surgical crisis, that I've ever been involved in," he said. "I've never seen cluster bomb injuries, I'd never seen incendiary injuries, as bad as they've got here ... (or) dealt with the massive bunker bombs that are being dropped at the moment."

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And this is what the 32 surgeons awaiting Nott's wisdom will return home to, the brave doctors helping the mass civilian casualties with equipment some would deem impossible to work with.

"It surprises me how well and stable and sensitive they are to normality. ... They've come out of the worst war zone you could ever possibly imagine," Nott said. "But I'm sure for their wives and children, seeing their husbands and fathers go off into a war zone trying to help civilians there and wondering whether he's going to come back alive must be absolutely heartbreaking."