By Carla Penman
Almost 600 children have had to be rescued from boiling hot parked cars so far this year - the highest number since 2013.
The Automobile Association says they've also had to rescue 494 pets from January through until September.
VetCare Grey Lynn veterinarian, Shalsee Vaigeant, believes the numbers are far higher than that.
"Those were calls that were made to AA to come out and unlock or help them get them out, that isn't animals that owners have come back and found that were struggling, it isn't people who've just forgot or people who did leave the windows down and were able to get back in," she says.
"So that's actually not the real number, it's going to be high."
NZH Focus spent just over six minutes talking to Vaigeant about the dangers - all the while, inside a steadily rising in temperature parked car with the windows up and air conditioner turned off.
The temperature outside was 26C, and inside, rose to 37C in that time.
Vaigeant says three minutes is too long for children and pets to be left in a locked or closed parked car.
She says it's even dangerous to leave them there with the windows down.
"Where we're seated, in between other vehicles and a building wall … even with these windows down, there would be no air flow and that temperature is going to get into the high thirties, just sitting even with the windows down," Vaigeant says.
"I think it's probably dangerous on a day in the middle of Summer, if you've walked out and thought 'wow it's warm', you should probably even consider not even bringing your pets in the car."
She says it's the same idea with children.
Vaigeant thinks there needs to be a drastic cultural shift in New Zealand.
She says people need to think about the heat and what they can do, before they park their car, so as to prevent putting their pets and children at risk.
"I think every year, we have these same numbers that go up and we get these same calls about heatstroke in pets and children left in cars but I think we need to keep re-educating," she says.
"As we get better and better at how we take care of our pets and even our children sometimes, I think that number will go down."