The Illawarra is set to sizzle in a statewide heatwave on Friday, with temperatures forecast to hit 35 degrees on the coast and up to 40 degrees in Albion Park.
A total fire ban has been declared for the region due to forecast hot and windy conditions. The ban will commence at midnight on Thursday and remain in place until midnight on Friday.
The Bureau of Meteorology has issued the Illawarra with a "severe fire danger" warning. Residents should check their Bush Fire Survival Plan and monitor conditions.
The weekend weather will be warm but rainy, with daytime forecasts between 24 and 29 degrees on Saturday and 26 to 33 degrees on Sunday.
The heat will stick around at the beginning of next week but drop off into the low 20s for Christmas Eve and Christmas Day, when the Bureau of Meteorology has forecast showers.
The heatwave - which hit Western Australia last week and has since moved steadily east - will affect most areas of NSW, leading various government agencies to launch a Heatwave Action Plan to help combat what they have called summer’s ‘‘silent killer’’.
Excessive heat causes more deaths than other hazards such as bushfires, cyclones and floods, research has found.
Police have warned motorists not to leave children, elderly people or pets unattended in cars, while NSW Health advised of several simple precautions to be taken during hot weather.
These included staying well hydrated, avoiding alcohol and hot or sugary drinks, limiting physical activity and trying to stay out of the sun during the hottest part of the day.
The health department said older people, as well as those who live alone or are socially isolated, were at greater risk of heat-related illness and should be contacted by family members during the next few days.
The NSW fire chief, Commissioner Greg Mullins, has also urged people to be fire safe over the festive season.
‘‘Unfortunately, at this time each year, firefighters find themselves very busy,’’ he said.
‘‘Over-enthusiastic decorating can see electrical circuits overloaded, which can cause devastating house fires.’’
‘‘Candles placed too close to Christmas cards and trees can lead to shattered festive dreams, [while] cooking left for too long in the oven or on the barbecue can create havoc.’’
He said there were 645 residential fires last summer between December 1, 2012 and January 31, 2013, which resulted in 72 injuries and two deaths.
The RSPCA reminded animal owners to take caution with their pets during high temperatures by providing plenty of water, shade, sunscreen and ensure they are free from fleas and ticks which can be a problem in warm weather.