Police smash window to rescue boy 'left in hot car for 40 minutes'

A toddler has been rescued from a locked car in an affluent Sydney suburb with police smashing a window to save him.

The boy, believed to be just two or three years old, was found dehydrated and visibly distressed inside the car parked outside a unit block on the leafy Powell Street in Neutral Bay about 11.15am on Thursday.

Officers broke the window of the car to rescue the toddler who is believed to have been inside the vehicle alone for close to 40 minutes, police say.

The boy's father told The Daily Telegraph he'd had "a rough night" and described the ordeal as "a disaster".

It's alleged a boy was locked in a car in Neutral Bay for 40 minutes. Source: 7 News
It's alleged a boy was locked in a car in Neutral Bay for 40 minutes. Source: 7 News

“I went to drop off my kid at the school; he fell asleep in the car," he said.

"I thought I had dropped him off and I went to work."

The boy's parents are being questioned, police said.

The incident prompted police and paramedics to again warn parents of the deadly consequences of leaving children in cars, especially in summer.

Even on a mild day, the temperature inside a car can reach upwards of 40C, NSW Police said in a statement.

"I recorded the temperature inside a car for some internal research last summer and it reached 78 degrees in just minutes," NSW Ambulance Chief Inspector Brian Parsell previously said.

The parents are being questioned, police said. Source: 7 News
The parents are being questioned, police said. Source: 7 News

"The situation can quickly cause damage to body cells leading to unconsciousness, shock, organ failure and death. Even in milder temperatures, children and babies can get sick very quickly."

The RACV also says tests show that on a 30C day, the temperature inside a car can rise to 70C in a matter of minutes.

A maximum of 28C was forecast for Sydney on Thursday.