The boy was treated by paramedics outside the pub, which was roped off by police and closed throughout the afternoon, as shown by photographs from local media channel Point Cook TV.
He was rushed to the Royal Children’s Hospital, where he remained in a critical but stable condition on Thursday morning.
A 32-year-old woman from Gladstone Park, north-west of Melbourne, was later charged with negligently causing serious injury and reckless conduct endangering life.
She was granted bail and will appear at Melbourne Magistrates Court on January 23.
Asked about a report the woman may have been inside the pub playing pokies, police spokeswoman Melissa Seach told radio station 3AW: “That will all be before the court.”
The incident comes less than a month after the state government launched a campaign warning of the risks of leaving children in hot cars.
Victorian Health Minister Jenny Mikakos expressed her disappointment in a tweet on Wednesday night: “I have no words,” she wrote.
From the start of November to December 20, there were 256 ambulance call-outs to locked cars.
On a 40-degree day just before Christmas, paramedics were called to five reports of children locked in cars in Melbourne.
According to the government campaign, called Never Leave Kids in Cars, a car’s temperature can more than double within minutes.
It also warns that a child’s’ body temperature rises three to five times faster than an adult’s, putting them at greater risk of life-threatening heatstroke, dehydration and organ damage.
Paul is a reporter for The Age.