Dad thought he dropped son at school before accidentally locking him in car

The distressed father of a boy trapped in a hot car in Sydney's north for more than three hours said he had a “rough night” and thought he’d dropped the child at school.

Police were called to the car in Neutral Bay on Thursday morning after neighbours noticed the child in the backseat at about 11am.

The car’s heavy window tinting may have made it harder to see the child but it also might have protected him from the heat as the day warmed up.

Officers smashed the window to get him out before the boy’s father arrived home confused and in shock hours later.

He arrived just before 2pm to find his car impounded with a note from police after he locked his son in the car.

The distressed father said he had “a very rough night” and “didn’t sleep”.

“I just dropped my kid off at the school,” he said.

“He fell asleep in the car. I thought I had dropped him off and went straight to work.

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“It's a disaster. I just want to go and see if my son's okay.”

Police said the toddler was only mildly dehydrated. He’s been treated in hospital and released. Doctors described his condition as “very stable”.

In a statement, NSW Police said an investigation is underway. The boy’s father is yet to be charged.