Winter blast in much of U.S. poses serious risks like black ice, frostbite and hypothermia.
Freezing temperatures and wind speeds are creating dangerously cold conditions in a large part of the U.S. stretching from Montana to northern Florida. The region is not expected to begin thawing out until Monday. In the meantime, forecasters are warning residents to be careful when outside. Weather risks include frostbite, hypothermia and falls and vehicle crashes. Black ice — the often invisible glaze that forms on roads, sidewalks and driveways — is of particularly concern in some spots. Home and business owners are also being warned to take precautions to prevent pipes from freezing and bursting.