Paramedics are urging NSW residents to look out for one another during this week's scorching conditions after being called to about 70 heat-related incidents across the state.
NSW Ambulance staff contended with cases of dizziness, fainting, heat stroke and heat exposure on Tuesday with most of the incidents involving people aged 60 and over.
However, paramedics were also called to treat a young child who was locked in a car in Greta in the Hunter Region.
A baby also needed to be rescued after being accidentally locked in a car at Sydney's Broadway Shopping Centre, according to NSW Ambulance.
Separately, a 14-year-old girl fainted and lost a tooth at Wattle Grove, in Sydney's southwest, while ambulance crews have also been called to many cases of people becoming exhausted after working in their yards during the heat.
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Some of the oldest patients have suffered from heat exhaustion, including a 92-year-old man in Beecroft, in northern Sydney, and a 91-year-old at Mount Austin, in Wagga Wagga
NSW Ambulance warned residents to stay out of direct sunlight, drink plenty of water and never leave children or pets in cars.
The heat has also prompted electricity provider Ausgrid to cancel planned maintenance outages on the Central Coast and Hunter region.
The state's northern inland region had recorded some of the hottest temperatures by the mid-afternoon, according to the Bureau of Meteorology.
Forecaster Rebecca Kamitakahara said the town of Bourke, in the state's northwest, reached 44.7C and Tibooburra Airport, in the far northwest, hit 45.1C.
"Generally anywhere west of the divide has seen temperatures at least in the high 30s, reaching into the mid-40s in places," Ms Kamitakahara told AAP.
Western Sydney had also endured scorching temperatures on Tuesday with Penrith reaching a new December record of 44.1C.
