Witnesses told police they found the girl, sweating profusely and crying, at 10 a.m. Monday in the parking lot of a Home Depot. The child was alone in the vehicle for at least 10 to 15 minutes, witnesses said.
The father rushed back to the vehicle when the store he was shopping in made an emergency warning about leaving children in hot cars.
When he returned to the vehicle, the crowd of witnesses yelled at the man.
Emergency services arrived and checked the child's health, the Canadian Broadcasting Corp. reported, and the mother took custody of the child.
Police and the Children's Aid Society were investigating the incident.
No charges had been leveled.
The incident occurred while much of the Toronto and York region was under a heat advisory. Police and public officials have warned parents that temperatures inside vehicles rise very quickly in hot weather.
Earlier this month, a 2-year-old boy died in Milton, Ontario, after he was left in a parked car.