Leaving a child in the car to go shopping is an error of judgement some have to regret forever. Credit:Justin McManus Meanwhile, 19 children were locked in a hot car in Point Cook, 18 in Frankston, 17 in Dandenong and 16 in Sunbury. Paramedics were called to help a record 1531 children locked in hot cars in the 11-month period. But even more alarming was the 50 per cent increase in the number of babies locked in cars. More than 370 babies under a year old had to be freed from a hot car by emergency services in that time. More than 190 children had to be treated by paramedics at the scene. In the eight worst incidents, the child had to be taken to hospital.

The majority of children left in cars - 88 per cent - are under the age of four. Nine in 10 children were under the age of four. One in four cases occurred in shopping centre car parks, or on a public road. About 20 per cent of incidents happened at home. The figures have prompted a blunt warning from Ambulance Victoria's director of emergency management Paul Holman.

"Tragically we've seen three children die in recent years after being left in a car on a hot day," Mr Holman said. "It's clear that leaving children in a car could prove deadly, yet people don't seem to understand the risks. "You wouldn't go shopping and then leave a tub of ice cream in the back seat of the car, so why would you leave your children there?" On a 29-degree day the inside of a car can reach 44 degrees within 10 minutes and hit 60 degrees within 20 minutes. Opening the window makes little difference to the internal temperature, tests by Ambulance Victoria show.

Earlier this month, celebrity chef Matt Moran cooked a whole lamb loin in the back seat of a car to prove just how high the temperature could soar inside a vehicle. "It doesn't matter whether you accidentally lock the keys in the car with your child or make a deliberate decision to leave the child in the car. The risks are the same," Mr Holman said. "Young children can't regulate their body temperature like we can. That puts them at significant risk and being left in a car can quickly become life threatening." Tim O'Connor, a paramedic and father of two, has developed a wireless device he believes will prevent trauma and save lives. The device is attached to a baby seat or seat belt and sends parents an SMS or alter, via a phone app, if the restraint is still locked once they leave the car. Mr O'Connor has patents pending for the invention and is looking for an investor to help him produce it.

Penalties for leaving a child unattended in a car include a $3690 fine or up to six months' jail. - with Suzanne Carbone