Baby left alone in warm car in Perth

A three-month-old baby boy has allegedly been left alone in a warm car at a Perth shopping centre car park for half an hour.

It is alleged the 35-year-old man left one window slightly opened at the Armadale Shopping Centre undercover car park on Wednesday afternoon before a concerned passerby heard the baby crying and called police.

The man has been charged with leaving a child unsupervised in a vehicle.

Police Commissioner Chris Dawson said the incident was an important reminder to the community as the weather is expected to heat up next week.

"The baby was hot to touch, but on being examined at the hospital, fortunately, the infant was able to be released to his mother with no health implications; but this is really concerning," he told 6PR radio on Thursday.

"I think this is an important early reminder to people. Do not leave children unattended in cars - they very quickly heat up."