With severe heatwave conditions predicted for NSW in the coming days, residents have been encouraged to develop a bushfire survival plan.
Police have also urged people to keep an eye out for elderly and disabled members of the community in cars during the coming days of extreme heat.
The Bureau of Meteorology has warned of extremely hot conditions across much of the state from Friday to Sunday and severe fire danger warnings have been issued for several regions including Sydney.
NSW Rural Fire Service spokesman Greg Allan says people should make their own bushfire survival plan as each household has different needs.
"Planning to have a plan is not a plan. You've actually got to sit down, work out plan. What would happen if it's the weekend, what if mum was at the shops? Dad was at the shops? Kids at sport, not just all sitting at home," he told AAP.
"As we saw with that fire just north of Newcastle, these things can start and spread pretty fast," he said of the last weekend's blaze that forced the closure of Newcastle Airport.
Temperatures are set to soar in western NSW on Thursday with Wentworth near Mildura reaching 42C and Broken Hill reaching 41C.
But the real heat is set to hit on Friday and the weekend while much of the state swelters in temperatures in the high 30s and parts of NSW reaching the mid-40s, BOM forecaster Jonathon How said.
The heat, he says, is the result of a hot-air mass making its way through the south-eastern part of Australia.
On Saturday the mercury is set to top 45C at Hay and Ivanhoe in western NSW and 43C in Penrith in western Sydney.
Ivanhoe will again swelter on Sunday with temperatures rising to 46C, while Scone in the Hunter region reaches 44C.
"Penrith and Richmond have already had eight days above 40C so far this summer, so they're well on the way to beating the all-time record of 12 days over 40C," Mr How said.
The NSW RFS has issued a severe fire danger warning for Sydney, the central ranges, northwestern NSW, the Illawarra, the Hunter and the southern and northern slopes on Thursday.
Tourists, campers and other holiday makers in unfamiliar environments are urged to take extra care, especially when swimming, police warned on Thursday.