Some 200 million Americans are feeling the icy grip of a massive winter storm that has been linked to at least 19 deaths ahead of the holiday weekend.
More than 1.5 million people lost power and thousands of flights were cancelled on Friday.
The vast storm extends more than 2,000 miles (3,200km) from Texas to Quebec.
A bomb cyclone, when atmospheric pressure plummets, has brought blizzard conditions to the Great Lakes on the US-Canada border.
In Canada, Ontario and Quebec were bearing the brunt of the Arctic blast, with power cut to hundreds of thousands.
Much of the rest of the country, from British Columbia to Newfoundland, was under extreme cold and winter storm warnings.
