Good Samaritans rescued two preschoolers locked in a hot car this afternoon after noticing one was overheating and in distress.

The young children had been left in the car at The Base shopping centre in Hamilton while their grandfather went to get lunch at about 1pm today, Waikato Police senior sergeant Charles Burgess said.

"Some good Samaritans fortunately saw one of the kids and went over and saw there were two there and saw one of them was in distress. They were very hot."

The shoppers rushed over and were able to unlock the car because one of the windows had been left partially down and removed them from the car.

"The grandfather turned up when the good Samaritans had them out of the car and I don't think he was too happy that bystanders had intervened," Burgess said.
Burgess said the young children were in the car for about 10 minutes before a shopper noticed.

Police and St John arrived and police are considering whether to lay charges. It is unknown whether the children were taken to hospital to be treated.

Hamilton is expected to reach a high of 30C today, according to MetService.