Firefighter Andrew Johnston grew up in the small rural village of Balmoral and was on duty when the Green Wattle Creek fire roared through there on Saturday.

Key points: Volunteer firefighter Andrew Johnston was on duty in his hometown of Balmoral on Saturday when the fire conditions were catastrophic

Volunteer firefighter Andrew Johnston was on duty in his hometown of Balmoral on Saturday when the fire conditions were catastrophic As well as fighting to save his neighbour's house, he came to the rescue when his crew mate called him having an asthma attack

As well as fighting to save his neighbour's house, he came to the rescue when his crew mate called him having an asthma attack With no end in sight for these fires, crew fatigue levels have become important to manage

The Balmoral Village Fire Brigade volunteer knew the properties he was protecting were the homes of his neighbours, friends and families.

Balmoral is one of the worst hit towns from the Green Wattle Creek Fire. ( ABC Illawarra: Tim Fernandez )

Mr Johnston said that when one of his crew fell to the floor he acted instinctively to protect his mate.

"One of our guys went down — he started having an asthma attack he called me on the radio and said 'I can't breathe! I can't breathe!'" he said.

"I pulled his mask off, pulled his helmet off, I got my flash hood out of my jacket, poured water on it and started cooling down around his face.

"One of the other guys in the truck also had heat exhaustion, so we dropped both off at the station and headed back out."

Properties saved and lost as firies pay ultimate price

Firefighters have saved dozens of properties in the New South Wales Southern Highlands, but many homes have been destroyed by the large out-of-control fire that tore through the region.

A combination of soaring temperatures above 40 degrees and erratic winds contributed to Saturday's catastrophic fire conditions which fuelled the Green Wattle Creek fire that has now burnt through more than 200,000 hectares of bush.

The fire first hit the region on Thursday, when two volunteer fire fighters were killed when their tanker rolled in the adjacent village of Buxton.

But the blaze returned with a vengeance on Saturday when Mr Johnston was on duty.

Catastrophic fire conditions helped the fire spread. ( ABC Illawarra: Tim Fernandez )

"It came through really quick — less than five minutes in the properties we were at," he said.

"We were putting out spot fires when the fire caught on the pine trees and suddenly there were flames of more than 100 feet.

"It was like a war zone."

The Balmoral resident recognised some of the homes he was protecting.

"We were fighting the fire at the McCanns' house, the fire was coming around us on all four fronts," Mr Johnston said.

"We ran out of water, so we filled up the truck with nearby bore water.

"I was filling up the water tank when the fire flared up at the back of the truck.

"I pulled the hose out and tried to put the flames out to stop the blaze from crowning."

Worst fire in memory

Fire crews on the ground were already stretched thin on Saturday when the southerly wind change brought a sudden change in the fire direction.

Mr Johnston said the region has had bad fires in the past — but none like this.

"I've been a firefighter for seven years, I've been to the Blue Mountains, I've been down to Ulladulla, and it doesn't compare to this," he said.

"I've never seen it this bad — the intensity, the heat, how high the flames were getting, how dry the conditions are, there's no rain."

Saturday's strong winds made the region's already dangerous fires catastrophic. ( ABC Illawarra: Tim Fernandez )

Mr Johnston was fighting the flames non-stop for nine gruelling hours.

"I went from 11 o'clock to eight o'clock at night and it felt like it was two days straight," he said.

"I can't tell you how many litres of water I had, but it was a shitload."

While he was out protecting other properties — his own home was impacted by the flames.

"At my home we lost a 40-foot container with all my grandad's tools that he made himself," he said.

Extent of damage unclear

Volunteer firefighter Andrew Johnston (left) and Deputy Captain James Cohens (right) have both been in the thick of it battling the blaze near Balmoral. ( ABC Illawarra: Tim Fernandez )

The cavalry has been called in to relieve exhausted fires crews including the Balmoral Village Fire Brigade.

Deputy Captain James Cohens, from the nearby Alpine Rural Fire Service station, said their job is to pick up where the other crews left off and begin taking stock of the extent of the damage.

"This area has been devastated, every second or third home has been destroyed," he said.

"It's bittersweet as some homes have been saved but a lot have been lost."

With no end in sight for these fires, Deputy Captain Cohens said it is important to manage crew fatigue levels.

RFS Deputy Captain James Cohens talks to Kelly Fuller about the ongoing fire fighting operation. ( ABC Illawarra: Tim Fernandez )

"It's been fatiguing on the guys, obviously everyone wants to get out and fight this thing at the beginning but it's important to understand this can go on for weeks if not months," he said.

Fire crews are taking advantage of the cooler conditions this week to make headway on the fire containment efforts.

Andrew Johnston said he was looking forward to spending time with his baby daughter over Christmas, but looking at the current conditions he is not holding his breath.

"I haven't seen my daughter for about two weeks," he said.

"So hopefully I can see her at Christmas, and it's her first birthday in a couple of weeks.