Minister for Children and Early Childhood Development Wendy Lovell has launched the No Exceptions, No Excuses campaign.
The campaign running in partnership with KidSafe Victoria, steps up the warning to parents and carers that leaving children inside parked cars - even for a moment - can be fatal.
"The temperature inside a car begins to rise as soon as you close the door - and within a matter of minutes - can be double the outside temperature," Ms Lovell said.
"This sort of heat can lead to devastating and potentially tragic results.
"We must remember that young children's smaller body size and underdeveloped nervous systems place them at a much greater risk of heatstroke, dehydration and other health problems compared to older kids or adults."
Ms Lovell said the campaign was in response to a recent increase in cases of children being left in hot cars.
Melanie Courtney, CEO of Kidsafe Victoria said that the 'No exceptions, No excuses' campaign provides an important reminder about how deadly the temperature inside a parked car can be.
"Particularly during the warmer summer months, it's important that messages about the dangers of leaving children unattended in cars reach as many families as possible" she said.
"It is important to note that some incidents occur when children are unintentionally locked inside a car. Parents and carers should always keep their keys on them when packing and unpacking the car to help reduce the risk of incidents like this occurring."
Minister Lovell said during the heat wave of January, Ambulance Victoria were called to 50 cases of children in cars.
"This follows troubling data from 2013, where paramedics were called to 1100 cases, 200 more than the previous year," she said.
Two thirds of all incidents were attributed to car parks, streets or public places.
"I urge anyone who sees a child alone in a parked car to raise the alarm and call emergency services," Ms Lovell said.
Ms Lovell said the awareness campaign aimed to reach Victorian parents and carers during the state's peak hot period, as they resumed their routines after the long school holiday break.
"It can be tempting to leave children in the car when making a quick stop at the shops, or doing the school pick up, but being away for even a moment can lead to serious harm or tragic results," she said.
"The message is clear - if you are travelling with a child in a car and you need to get out, make sure you take your child with you. No exceptions. No excuses."
Victorian legislation makes leaving a child unattended in a car a criminal offence, with penalties ranging from fines of $2165 or three months in prison.
For more information go to kidsafevic.com.au