Department spokesman Steve MacDonald said the boy was helping his father shovel the snow in the Dorchester neighborhood Saturday but got cold, so his father started the car and the boy got inside. MacDonald said the car exhaust was covered by a snow bank, causing the fumes to collect in the vehicle.
When the boy was overcome by the fumes, the father went into respiratory arrest and emergency workers took both to Boston Medical Center. The boy was pronounced dead at the hospital. No names were released.