Smoke billows from the catering building and you can already hear the pained screams.

You move through each pitch-black room, tripping on debris, trying to triage desperate patients with everything from blast injuries to severed limbs.

99 Red Balloons is blaring on repeat.

It’s not what the nursing officers on the ADF extended practice nursing course expected – or wanted – after a hard workout at Latchford Barracks, Bonegilla, last month, but it’s what they got.

Thanks to staff at the Health Specialist Wing of the ADF School of Health, what used to be a table exercise has been transformed into a fully simulated activity.

Moulage, a smoke machine, dedicated role-players and the assistance of local emergency services all combined for the desired effect – realism in training.

Flying Officer Naomi Grey said the scenario was set around an explosion inside a catering building, resulting in all levels of casualties.

“Injuries, patients wandering off into the bush, we had media trying to get in, there was someone with a rifle at one point,” Flying Officer Grey said.

“It has been chaotic, nothing short of. You have a baseline understanding of what you're meant to do, but then applying it at full speed, it's quite challenging.

“As opposed to a tabletop exercise when everyone's there, you have actual teams in different locations that you can't access; radio chatter; you have people that need to send through casualty reports and other people trying to communicate other things. It's very overwhelming.”

Lead instructor Lieutenant Chau Tran said getting trainees used to equipment, experiencing sensory overwhelm and the physical nature of the job – all while holding weapons – was invaluable.

“In a stressful environment you tend to create mistakes and it's better for you to create a mistake in a training environment where we can test and adjust than for it to happen in real life,” Lieutenant Tran said.

“This sort of scenario can happen at any time, and as a service member – when you're wearing this uniform – you're always ready to go.”

The course is the culmination of training for nursing officers in Defence, with the mass casualty event held at the end. 

After completing their nursing degree, trainees are posted to units across Australia as of the beginning of November.