An extreme cold snap has hit much of the United States, causing widespread power outages, flight cancellations, and car accidents.

The frigid temperatures are expected to bring the coldest Christmas Eve on record to several cities, including Pittsburgh, Athens, and Charleston, according to the National Weather Service.

The forecast in Pittsburgh calls for a high of just 7 degrees Fahrenheit (minus 13 Celsius), breaking the previous record of 13 degrees Fahrenheit set in 1983.

In Athens and Charleston, the coldest daytime Christmas Eve high temperatures are expected, while Washington D.C. is forecast to experience its coldest December 24th since 1989.

The deep freeze, exacerbated by dangerous wind chills, has already resulted in fatal car accidents across the country, with at least 14 weather-related deaths reported.

The arctic cold, combined with a “cyclone bomb” of heavy snow and strong winds, has disrupted power systems, roads, and air travel.

The extreme winter weather has been blamed for at least five deaths on Friday, including two motorists killed in a 50-vehicle pileup on the Ohio Turnpike and three fatalities in Kentucky. Freezing rain and ice in the Pacific Northwest have also made travel difficult in the region.

Across the country, some 240 million people were under winter weather warnings and advisories on Friday, according to the National Weather Service, which described the extent of these warnings and advisories as “one of the greatest” ever.

The severe weather has disrupted the plans of millions of Americans and left as many as 1.8 million homes and businesses without power, according to tracking site Poweroutage.us.

A total of nearly 4,000 flights were delayed and over 5,000 were cancelled on Friday, according to FlightAware.

The city of Buffalo and surrounding county in western New York have imposed a driving ban and closed all three border crossing bridges to inbound traffic from Canada due to the weather.

Authorities have opened warming centers and expanded temporary shelter for the homeless, including migrants who have recently crossed the southern border of the United States in large numbers.

The challenge of providing shelter has been compounded by the influx of migrants and the strained energy systems across the country, which are struggling to meet the rising demand for heat and dealing with storm-related damage to transmission lines.

The bitter cold, combined with high winds, has extended through the Deep South to the border with Mexico, with wind chill factors reaching single digits Fahrenheit in El Paso, Texas.

Exposure to such extreme conditions can cause frostbite within minutes. The American Automobile Association had estimated that 112.7 million people planned to travel 50 miles or more from home between Friday and January 2nd. However, the stormy weather is likely to have kept many of them at home.