A 9-year-old boy died from heatstroke after becoming trapped in his mother's car for about one and a half hours on a sweltering day in Nara, officials from the local prefectural government said Tuesday.

The boy was found unconscious on Monday afternoon inside the locked car in a parking lot in the city. He was rushed to hospital by ambulance but was pronounced dead in the early hours of Tuesday.

The boy's mother was quoted by the officials as saying that she went to a nearby hospital at around 1:30 p.m. after handing her car keys to her son and telling him to come later, while leaving the windows closed and engine shut off.

After returning to the parking lot, she found her son collapsed and immediately called an ambulance. The emergency crew had to break the car's window to free the boy.

The temperature in Nara reached 34.1 C at its peak on Monday, according to the Japan Meteorological Agency.

Source: ANNnewsCH