Midwesterners braved bracing winds as they continued to dig out driveways and stranded vehicles and rushed to stock up on last-minute gifts and provisions hours ahead of Christmas Day.

Although many roads were choked with snow and major tailbacks, the region's airports appeared to be only slightly affected. Chicago's O'Hare International Airport, the Midwest's busiest hub, was functioning with few problems, according to the Federal Aviation Administration.

Airlines also reported few delays.

However, the chilling Christmas assault from Mother Nature seemed set to continue.

"Arctic air moving over the relatively warm waters of Lake Michigan will result in a continuation of lake-effect snow showers over far southwest lower Michigan today," the National Weather Service said in one of several weather warnings.

"The combination (of) very cold air and winds around 10 miles per hourkilometers an hour) will cause wind chill temperatures to become bitterly cold and reach hazardous levels tonight and Christmas morning," the weather service said.

Snow, winds and ice have been particularly harsh across Illinois, Indiana, Michigan, Missouri and Ohio, and traffic on some key interstate highways has been cut to a single lane in some places, with record snowfalls seen in certain regions.

The US Postal Service said post offices would be open Friday, but the harsh weather has snarled some last-minute deliveries of Christmas cards and presents.

"In some communities, delivery will be dependent on local road conditions," the postal service said.

Parcel delivery giants UPS and DHL were also vying to keep Christmas deliveries on track.

Due to flight delays out of Louisville, Kentucky, earlier this week, sparked by snow and ice, UPS said it might not be able to deliver packages due on doorsteps Saturday.

DHL said its deliveries through the Ohio Valley could be badly affected, noting in a statement that it could no longer guarantee that parcels in the region would arrive by Christmas Day.

The National Weather Service issued a "hazardous" advisory for north-central and northeastern Illinois and northwestern Indiana, warning of wind chill factors of around five to 15 degrees below zero (minus 20.5 to 26.1 degrees Celsius).

Other advisories warned that rivers might well burst their banks due to "ice jams," while Indiana State Police warned that Interstate 80/90 was covered in ice and that several other key highways were also "becoming snow or ice covered."

In Ohio, ice storms have downed trees and power lines, and at least 36,000 people remained without power Friday in the Canton, Wooster, New Philadelphia and Coshocton areas, according to a statement on American Electric Power Inc.'s website.

"Crews worked through the night in frigid, icy conditions," the power company said.

The cold-weather snap made the front pages of many US newspapers and likely caused some stranded motorists to wish they could hitch a smooth lift out of trouble on that legendary reindeer-pulled sleigh.