At least 16 deaths have been blamed on a winter storm that dumped nearly 2ft of snow in finger-numbing temperatures in parts of north-east America.
Fourteen deaths have been blamed on the storm.
By yesterday morning, about 2,200 flights had been cancelled nationwide, according to the aviation tracking website FlightAware.com.
Governors in New York and New Jersey declared states of emergency, urging residents to stay at home.
Hundreds of schools were shut down in Boston and New York, extending the holiday break for tens of thousands of students.
"This is nothing to be trifled with," New York Governor Andrew Cuomo said.
"People should seriously consider staying in their homes."
A massive pile of salt fell on a worker at a Philadelphia storage facility, killing him. And authorities say a woman with Alzheimer's froze to death after she wandered away from her rural New York home.
Forecasters said temperatures were plummeting to well below freezing and wind chill readings could hit -23C.
Another wave of cold air was already moving through the Midwest from Canada.
Outreach teams were searching streets in New York City and Boston for homeless people at risk of freezing to death.
Some major highways in New York state were shut down overnight, and some commuter trains around New York city were operating on a reduced schedule.
New Jersey Governor Chris Christie ordered non-essential state workers to stay at home. State offices and courthouses were closed. State offices were also closed in Massachusetts.
Meanwhile, bad weather continued to wreak havoc across Britain, where the country's Environment Agency yesterday issued nine severe flood warnings -- where lives could be at risk -- in the South-west, Wales and the Midlands.
The rivers Stour in Dorset and Severn in Gloucestershire burst their banks, while Scotland was last night bracing itself for wind speeds of up to 80mph as storm surges moved north.
Looe in Cornwall, Ilfracombe, Barnstable and Plymouth in Devon and Caernarfon in Wales were among the towns which found themselves partially submerged.