A toddler and baby were found sweating and distressed after being left locked in their car in Napier's 33 degree heat on Sunday.
Chrystal Alatasi found the children hot and distressed inside the car at a Napier supermarket while their mother shopped.
She took to Facebook to express her anger about the situation.
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"Disgusting mother from Dunedin left her two kids in a car with windows up and doors locked for half an hour to do shopping at Greenmeadows New World," she wrote.
"...Distraught and sweating profusely. All cop's did was give her a warning. Thank God daughter was old enough to open door, 33 degrees, makes me so angry."
Ms Alatasi told NZME she had just finished packing her own groceries when she heard crying and then made the shocking discovery.
She desperately tried to open the car doors but ended up calling 111. The call taker asked if the toddler could open the door from the inside which she did with Ms Alatasi's guidance.
Ms Alatasi have been contacted for comment.
A police spokesperson told Newshub the children's mother was given a formal warning and a report will be made to Oranga Tamariki.