The Richmond Police Department said officers responded to a call of an unresponsive child in the 100 block of Douglas Street.
According to police, the victim's family noticed he was missing and later found him in a family vehicle.
Family members rushed the child to the Oak Bend Emergency Room, where he was pronounced dead.
Police told Eyewitness News the vehicle was off and hot when the boy was found. The incident is being investigated as heat-related.
The temperature was forecasted to top out at 97 degrees in the Fort Bend County town. The National Weather Service already issued a heat advisory through 9 p.m. Saturday, with heat index values potentially reaching 111 degrees.
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