NEW YORK -- Bone-chilling cold has prompted schools around the Northeast to delay openings and some canceled classes all together on Monday, as an Arctic cold front extended its stay in the region.

Schools in western and northeastern Pennsylvania, across upstate New York and parts of Vermont and New Hampshire closed their doors or delayed openings to protect students from temperatures that dropped in some locations as low as 25 degrees below zero or even colder.

The wind chill in some areas of New England was expected to make it feel as cold as 50 degrees below zero.

The cold snap was linked to at least two weekend deaths in the Northeast, including that of a woman whose frozen body was found in a driveway.

In upstate New York, the National Weather Service issued wind chill advisories and warnings for much of the region, including the Adirondacks where the low was 36 below in Saranac Lake early Monday morning.

Wind chill advisories were issued for much of western New York, and forecasters in some northern areas said it felt like 40 below with the wind chill.

Layered clothing was the order of the day around New Jersey as temperatures dropped to single digits or below zero. In Newark, N.J., the wind chill made it feel like four below zero.

The National Weather Service predicted a high of 20 in New York City, but problems were reported at New York City's LaGuardia and Kennedy airports early Monday morning.

The Metropolitan Transportation Authority said it took extra steps overnight to ensure that its commuter trains and subways and buses would run without problems for the morning rush.

Extra crews checked on signals and switches and deicer and scraper trains were run to ensure ice did not build up on the rails. Some subway trains were stored underground and buses were checked for any equipment problems.

The thermometer was at minus-6 degrees around 6 a.m. Monday in Mt. Pocono, in eastern Pennsylvania. Subzero temperatures were also recorded in western Pennsylvania, where the National Weather Service issued an advisory over wind chills as low as 20 degrees below zero.

In Philadelphia, a group of determined parents waited on a sidewalk overnight to enroll their children in kindergarten at a prestigious school run in partnership with the University of Pennsylvania. The Penn Alexander School eventually opened its doors, letting the parents in from the cold.

About 90 miles northwest of Philadelphia, a man died after spending the night in his car in frigid temperatures in Lansford, and his wife found him Saturday morning. Temperatures had dropped into the single digits overnight, but it's unclear why 49-year-old Alan Kurtz had slept in his car.

In North Haven, Conn., a woman's frozen body was found in a home's driveway Sunday morning after a neighbor called police. Denise O'Hara apparently fell in a driveway and froze to death Saturday night, when temperatures were close to zero, police said.

In Pittsburgh, where the Pittsburgh Steelers beat the New York Jets in the NFL playoffs Sunday evening, the temperature was about 13 degrees at game time.