Firefighters from the Bowral branch of the Rural Fire Service have reminded Southern Highlanders that outdoor heaters should not be used inside.
The firefighters said the use of outdoor heaters in the home was dangerous.
Outdoor heaters are not designed for the lack of ventilation indoors.
A propane gas heater produces carbon monoxide, nitric oxide, and nitrogen dioxide.
The risk of carbon monoxide poisoning is high while using an outdoor heater in a poorly ventilated space.
A person with carbon monoxide poisoning will have persistent tiredness, shortness of breath, headaches, nausea, vomiting, and loss of consciousness.
These gases if inhaled in excessive amounts can be fatal.
Indoor heaters are specifically designed for heat distribution and safety in an enclosed area.
The RFS has urged residents to put safety first when keeping warm in winter.