Los Angeles: A 14-year-old Massachusetts boy died on Saturday of carbon monoxide poisoning after warming himself in a running car while his father shovelled snow.

Boston’s mayor promptly issued a new warning of the perils associated with the massive Northeast blizzard.

The boy had been helping his dad shovel snow on Saturday near the family’s sedan, and hopped into the running car to warm up, Boston fire spokesman Steve MacDonald told The Times.

But a mound of snow had blocked the exhaust pipe, preventing the poisonous carbon monoxide from escaping, MacDonald said.

When firefighters arrived at the family’s Boston home around noon Saturday, neighbours had already begun CPR on the boy, who they said had gone into cardiac arrest.

Meanwhile, the boy’s father went into respiratory arrest, for reasons that were unclear, and both of them were taken to a local hospital, where the boy was declared dead, MacDonald said.

Mayor Thomas M. Menino used the boy’s death, which he called a “tremendously sad accident,” as the back-drop of his Saturday afternoon plea to the people of Boston: “The danger of this storm is not over.”

“Please take care and use caution when cleaning up and getting back out on the streets,” Menino said. “Our hearts go out to that family and their friends.”

In addition to imploring people to remove snow around their exhaust pipes before turning on their cars, Menino reminded residents to avoid using generators indoors, to use flashlights instead of candles and to shovel fire hydrants out of the snow. The winter storm lashed northeast states overnight Friday and Saturday morning before moving out to sea, leaving behind 2 to 3 feet of snow.