Eight people have been taken to hospital following 11 house fires overnight - most of which were caused by chimneys or heaters, authorities say.
The incidents prompted Fire and Rescue NSW to warn residents to be careful when heating their homes ahead of one of the most significant outbreaks of cold weather in 60 years.
"Our firies don't want to see more people on the casualty list so please remember to keep looking when cooking and don't leave your heaters, dryers, electric blanket or any other electrical appliance unattended," Fire and Rescue NSW said on its Facebook page.
"Always turn them off when leaving home or going to bed and check the electrical cords for fraying and other damage."
Two of those hospitalised included police officers who ran into a burning home in Lugarno after they were told some of its inhabitants were still inside.
But all five occupants had already made their own way out of the Elm Street home, police said.
A 52-year-old woman and a 16-year-old girl who lived at the address were taken to St George Hospital for treatment of smoke inhalation, as were the two officers.
The fire, which was not deemed to be suspicious, was believed to have been caused by a faulty power board, police said.
One room was destroyed by fire before the blaze was extinguished.
Fire and Rescue's Facebook post also warned against using outdoor heating and cooking appliances indoors.
"This includes appliances that use heat beads or LPG as a fuel source," the post said.
