An elderly man has been taken to hospital after a gas heater malfunctioned at a Barrack Heights home on Thursday afternoon.
Emergency services were called to the single-level home on Keross Avenue just before 2pm, following reports of a gas bottle explosion and subsequent fire.
A Fire and Rescue NSW (FRNSW) spokesman said three crews responded to the fire, which was located at the rear of the house.
Two people, a 92-year-old man and a 50-year-old woman, were assessed by paramedics at the scene.
A NSW Ambulance spokeswoman said the man was treated for smoke inhalation and minor burns to his right hand.
He was taken to Wollongong Hospital for further treatment.
The woman who came to the man's aid, Deb Murray, was treated for smoke inhalation.
Ms Murray said she was leaving work at nearby Warilla High School, when she smelled smoke and pulled up outside the house, with her son Jett in tow.
She said she saw the front door was open and immediately went inside, while Jett called Triple-0.
"It was quite thick smoke, so I went in there and I was yelling out 'is anybody home, is anybody home' and I could hear noise," she said.
"One of the doors was shut but the smoke was getting too thick by then and I heard the elderly man so I was able to get him out onto the balcony.
"I ran next door to see if there was anybody home ... because I wasn't sure how far it [the fire] was going to go."
Two other people from the school also assisted the man.
"He was in shock and he was singed, he was burnt. He looked a little bit puffy in the face ... his hand was bleeding and burnt," Ms Murray said.
Jett said he was shocked by what unfolded.
"I just dialled Triple-0 as soon as possible to make sure that he was cared for and everything was taken care of as soon as possible to minimise the damage, but it was a shock to me," he said.
"It's not something I've ever experienced before."
FRNSW Shellharbour station officer Murray Oastler said crews arrived to find black smoke billowing from the roof and out the front door.
"As we've gone around the back we've found some LPG cylinders, one was alight. It appears to be some sort of malfunction with an LPG heater that's caused the fire," Mr Oastler said.
"We were able to knock it down pretty quickly and control the heat in the cylinders.
"There were some LP gas cylinders out the back that were impacted by the heat.
"We didn't find any exploded ones, some sort of small explosion might have been what lit them in the first place."
The Mercury understands nearby Warilla High School was put into lockdown due to a significant amount of smoke in the area.
The incident closed sections of both Keross Avenue and Daphne Street.
Mr Oastler urged people to be careful with LPG appliances.
"It's highly explosive, make sure all your connections are tight, make sure everything's in date, your hoses are in good condition and that you've got a standard, compliant appliance that you're using," he said.