MONTPELIER, Vt. — Train equipment froze, cars sputtered, schools canceled classes and cold-weather enthusiasts opted to stay inside Monday as a bitter blast of below-zero temperatures gripped the Northeast.

The gasp-inducing cold – temperatures reached into the minus-30s with wind-chill factors even colder – tested the mettle even of New Englanders, who pride themselves on winter hardiness.

“Snot-freezing cold” was how Kelly Walsh, 28, described it, walking home from an auto parts store in Vermont’s capital after buying a new battery for her car, which wouldn’t start Monday morning. It was minus 21 there at 7 a.m.

“I usually really like it,” she said. “Today is a bit of nuisance.”

Schools in western and northeastern Pennsylvania, across upstate New York and in parts of Vermont and New Hampshire closed their doors or delayed openings.

Amtrak suspended service between Albany and New York City, saying the extreme cold affected signals and switches. It hoped to resume service today, when the cold was expected to ease but begin to give way to a potentially huge snowstorm.

In New York, the city doubled the number of outreach vans it sends out looking for homeless people in such cold, checking on street people every two hours.

“Our priority is to make sure they’re safe and warm,” said Seth Diamond, commissioner of the New York City’s Department of Homeless Services.

In Providence, R.I., it dipped to minus 1 early Monday, the first below-zero reading there in six years, the National Weather Service said.

In Lebanon, N.H., a homeowner thawing frozen pipes with a torch in the basement set an 11-unit apartment building on fire. It was minus 20 Monday morning when the torch sparked the fire, which spread quickly. No injuries were reported, but several pets were missing.

Throughout the day Monday the temperature rose only to minus 4 in Newport in northern Vermont and 1 degree in Burlington and Montpelier.

In Massachusetts, Cape Cod and neighboring islands were the warmest areas at 17 degrees, National Weather Service meteorologist Eleanor Vallier-Talbot said.

In Connecticut, Bridgeport and New Haven also reached 17 degrees.

Wind-chill advisories and warnings were issued in upstate New York, including the Adirondack Mountains, where Saranac Lake posted a reading of minus 36 early Monday.