The advice comes after a baby was found crying in his car seat inside a locked car, parked at a Hamilton supermarket on Monday.
A shopper at the Countdown on Anzac Pde heard the baby crying around 11.20am and rushed over to find the distressed child in the seat beneath a plastic cover.
The store made announcements and one staffer rang the police, the woman, who did not want to be named for fear of a backlash, said.
“We were tapping and knocking the window to try and get the baby to stop crying. Because of the plastic cover I thought it would get quite hot in there,” she said.
Eight minutes passed before the mother appeared with her shopping.
The mother then put her groceries in the car and drove off before any bystanders could do anything further, the witness said.
“I understand leaving your kid for a minute or whatever, but it just felt like forever.
“I don’t know how long the car was parked there before I got back to my car.
“If it had been any longer I probably would have done something to break the window open. She came out just as I was kind of thinking of what to use.”
The baby would have been aged between zero and four months, the woman said.
“It was quite distressing and quite hard. I’m still hearing the little baby’s scream ringing in my ears.”
SafeKids spokesperson Anthony Rola said the advice to all parents is: “never leave a child in a car”.
“Even for a minute – don’t leave babies in the car – it’s very straightforward.
“It’s just not safe for them to be by themselves in the car.”
He advised parents that, even when filling up with petrol, it was advisable to take your child into the petrol station.
“Taking them out of their car seat and bringing them into the petrol station where you pay is safer than leaving them by themselves in a car.”
Plunket national advisor of child safety Sue Campbell said there was no minimum amount of time that was safe to leave a child of any age in a car.
“Often adults think they will be gone for only a few minutes and it ends up being a lot longer.”
Research shows that small children heat up about three to five times faster than adults, she said.
“A small child will get hotter a lot faster than an adult, and get more dehydrated, which can lead to heat stroke when in a hot vehicle.
“Even in winter the inside of a vehicle will still heat up – you are still going to get an increase in temperature and if the baby is distressed there is more propensity for the child to become dehydrated.”
She said anyone who sees a child alone in a vehicle should alert authorities.
“Then they can alert the powers that be if anything happens.”
In Australia, it is illegal to leave a child unattended in a vehicle, the woman who found the child said.
“I’m a mum myself and it’s a bit heartbreaking. I would never, ever leave my kids in a car unattended,” said another woman, in the carpark at the time, who also declined to be named.
“It’s quite muggy outside too, so god knows what the temperature was like inside the car.”
When asked about the incident, Countdown responded with a statement from spokesperson Kate Porter.
“We’re aware of this situation, and are pleased that it was resolved quickly.”
A police spokesperson said they received a call about a child aged between 0 and 5 months in the car but the mother arrived while the caller was on the phone.