A THREE-month-old baby has died after he was allegedly left in a boiling car when his mum forgot to drop him off at nursery on the way to work.

Little Aiden Miller was unresponsive when his mum discovered he was still in the back seat of the vehicle in New Albany, Indiana, at about 4.30pm on Monday.

She called emergency services and he was taken to Baptist Floyd Hospital where he was pronounced dead.

His dad, Aaron Turner, last night revealed the horror after the child's mother, who has not been named, found him in the car after leaving work.

Mr Turner told Wave News: "She said she opened the car door and was like, 'What is that smell?' and she noticed Aiden was still in the back seat."

The grief-stricken dad claims the child's mother, who he is reportedly separated from, was supposed to drop off their two children at separate nurseries.

She had apparently taken their two-year-old daughter to one daycare but tragically their youngest child didn't make it to his nursery two miles away.

He was later found inside the vehicle, which was in the car park of Express Care Medical Center in New Albany.

Mr Turner told WLKY his ex had "forgotten" that little Aiden was still in the back.

He said: "I still don't understand how that happened. Obviously it happens. It just happened in my family. It doesn't get any closer to home than this."

He told how he feels mixed emotions after the tragedy, adding: "It is inexcusable for any kid to have to go through and for parents to have to lose a child like this."

Mr Turner told WLKY: "My heart is broken. My biggest hope is in sharing this story, another child's life will not be lost."

He also said his son was a great baby who did not cry unless he was hungry, adding that he was just beginning to smile at the sound of his voice.

The New Albany Police Department Criminal Investigations Division is investigating the child’s death and no arrests have been made.