Here's the situation. Somehow, you've locked the kids in the car. You might have been sleep deprived, accidentally done things in the wrong order, perhaps locked the car then thrown the keys inside the car before getting the children out.
It could also be the car's fault - there have been rare occasions where they've been known to be temperamental and lock shut. Whatever has happened, the children are inside and you are outside. When does this turn into a drama?
Cars can heat up faster than you realise - on a 20 degree day, the temperature inside the car can get to 60 degrees, and 75 per cent of that temperature rise will happen in the first five minutes. On a hot day, the stats get even worse. 30 degrees outside turns to 70 degrees inside. An internal body temperature of 41.7 degrees is considered lethal for humans, and Victoria recently doubled their maximum penalty jail time to highlight the problem, after three children died from being left in locked cars.
Children also heat up three to five times faster than adults so they are more likely to have organ damage or failure, quickly.
So, what should you do?
The first thing to do is call the police. They will send help immediately. The NRMA also makes it first priority to send help when a child has been locked in a car, so they too will respond quickly, but the police need to come anyway to check how this happened, so you will have to call them as well.
If your child hasn't been in the car long and it’s relatively cool, the NRMA will try and pick the lock and get them out without damaging the car.
But if your child is distressed you should request an ambulance while you're calling the police, and - follow your instincts here - you should break the window. The advice is to break the window if they are obviously in distress or their health looks like it's failing. If you do need to break the window yourself, choose the window furthest away from them. Your main priority is to get your child out of the car as quickly as possible and cool their internal temperature.
If you come across someone else's child (or a pet, pets also die in this way and need to be rescued) in a locked car and you can't see the parents, call the police. You should also make a judgement decision if the child is distressed as to whether or not you'll need to break the window. The bottom line is, if a child is in distress or their health is in danger, get them out of the car as quickly as possible.