"Get down! Get down! Stop. What are you doing?"

A group of six foreign aid workers freeze, dead still, on the rugged path, while another armed fighter with a balaclava closes in from behind.

The six are members of a Red Cross team, trudging back from a nearby refugee camp. More than 1000 people are crowded in the camp, complaining of little food, filthy pits of sewage, and no medicine.

The Red Cross team wanted to help the desperate – only now, they are themselves the ones under desperate threat.

The masked rebels here are trainers, the guns are not real. The refugee camp is a clever concoction in the damp eucalypt forest at Yellingbo, about an hour-and-a-half drive east of Melbourne.

The aid workers are being schooled in the potential dangers of doing good.

The encounter is modelled on what has become an increasingly familiar scenario in messy modern conflicts, where humanitarian workers are caught in the crossfire or even deliberately targeted.

An aid convoy from Red Cross was forced to turn back from a besieged city in Syria last week after baby milk and other food was confiscated at a military checkpoint.

This week, an Australian man working for a land mine clearance charity was killed in northern Iraq, reportedly as he attempted to defuse a bomb.

Other threats can be insidious. Last month, Australian aid worker Kerry Jane Wilson was kidnapped at gunpoint in Afghanistan, after two men claiming to be local officials arrived at her office in the eastern city of Jalalabad in the early hours of the morning.

Taking foreign hostages for ransom can be a lucrative business. In January, extremists claiming to be from al-Qaeda snatched Australian surgeon Ken Elliott and his wife Jocelyn in the west African nation of Burkina Faso, where they had worked for decades. (Jocelyn Elliott was released soon after. The couple are aged in their 80s.)

The aid workers at the training course are told they are never expected to accept risks which they find uncomfortable.

But why put their lives in danger at all?

Shane Wilkes is one of the six. He has a background in organising water supplies and sanitation, but is relatively new to the business of humanitarian work.

"In any circumstance, the need is the greater concern," he says, "It's part of the job."

Even when the armed rebels jumped out, Wilkes said, "I'm thinking about those people in the camp."

It's a fascinating conundrum for people wanting to save the world balanced against the necessity to be protected from the worldly threats.

Paul Keen, Asia Pacific co-ordinator for the International Committee of the Red Cross, said the training was meant to be realistic: "They live out as much as possible the experience they are going to have in the field".

Fairfax Media was allowed to observe the training, a course known as "Impact" and designed to prepare aid workers ahead of deployments to a potentially hostile environment.

What danger they will face is mostly a consequence of suspicions. It might be an overly officious military commander, or more often than not, a shakedown to steal relief supplies.

Any potential danger should be well explained by a local Red Cross security specialist before going a mission.

The action might be far way, but there are people at home to consider, too.

Claire Hallas, another of the Red Cross team, said it was important to have a frank conversation with family, to explain the reasons for taking a risk to help others. The idealist goal, to make a difference.

Hallas is pleased the training offers the chance to put into practice advice that would otherwise be just another lecture.

And there is plenty of advice. Avoid protests or demonstrations. Watch the profile of police, how they are acting. In some places, the police or security forces are the threat. Ignore catcalls or verbal bait.

It might be tense, the aid workers are told, but it is important to respond to facts and data, not emotion.

Common sense is key.

"Never be isolated, never be on your own. If someone needs to go to the toilet, we go as two."

The six aid workers are preparing to travel to the refugee camp. A sheet of butcher's paper is spread over a small table in a crowded office and they plan what they want to ask.

How many people? What are the health needs? Common questions, to ask of as many refugees as they can.

But they also decide who will do the talking to figures in authority. Stick to the safe paths, be wary of landmines.

The message is simple. Planning, planning, planning.

The imagined setting is the aftermath of a natural disaster, a tragedy in the midst of a conflict between two neighbouring countries, Alphaland and Longonia.

The six aid workers arrive at a checkpoint outside the camp, confronted by a man in camouflage gear with a pistol, and another bullish thug without a uniform but a stick and a sneer.

"Put your supplies down," the military man orders. "My soldiers need supplies." After a short negotiation, and promises to speak later, the aid workers are allowed into the camp, the thug menacingly alongside.

The aid team is allowed only 10 minutes amid the tents. An apparent leader of the refugees approaches, a woman in grey with demands. "We're hungry. We need water." But the aid workers later come to fear she might be acting in collusion with the military man.

One aid worker keeps the thug talking, or tries, while another speaks to the woman in grey. The remaining four manage to drift away, each alone, and quietly speak to other refugees.

Was separating a mistake? Perhaps, but also an insight into the difficulty of collecting reliable information when tensions are high. After a rushed survey, the group settle on a figure of 450 men and 550 women in the camp.

Aid groups have been criticised at times for exaggerating the scale of an emergency. But underestimating is as much a risk.

All the while, real or imagined, the military man's words hang in the air.

"This is a very dangerous place. I hope you know how dangerous it is."