The NRMA urged parents to think twice before leaving children or pets unattended in cars, as temperatures are set to soar past 30 degrees.
Despite repeated safety messages, NRMA research shows more than 50 per cent of parents are still leaving their children unattended in vehicles to pay for fuel or duck into the shops for milk.
On a typical Australian summer day, the temperature inside a parked car can be more than 30 degrees hotter than outside the car.
That means that on a 40 degree day, the temperature inside a car can reach over 70 degrees.
This year, the NRMA has rescued more than 2000 children and 1500 pets from cars, however, the majority of these cases were accidental with parents locking their keys along with their children in the car.
NRMA Patrols are highly trained to get into cars with children locked inside, with many able to have a car unlocked in a few short minutes.
NRMA road safety expert Dimitra Vlahomitros said it was never worth the risk to leave children in the car to grab a quick offer or pay for fuel.
"At high temperatures like those we experience in much of NSW, it only takes a few short minutes for children to become dehydrated and distressed," Ms Vlahomitros said.
"While it's tempting to leave the kids strapped in to quickly run into to pay for fuel - it can be a recipe for disaster. Where possible, look for petrol stations where you can pay at the pump.
"If you see a child unattended in a car and cannot locate the parents, call triple-zero and await instructions. If the child or pet is clearly distressed, and you have no time to wait for the police or an NRMA patrol, find a way to safely break a window."
NRMA patrol Matthew Nesbit said the NRMA received thousands of calls a year from frantic parents who have accidentally locked their children in the car.
"As soon as a call comes into our call centre about a child locked in a car it's immediately put to the top of our job list, regardless of whether they are members or not," Mr Nesbit said.
"When we arrive, it's usually the parents who are more distressed than the children inside the vehicle. A trained NRMA patrol can usually have the car open within a few minutes. Best thing to do in this situation is not to panic, just pick up the phone and call us immediately."