Governors in New York and New Jersey declared states of emergency and urged residents to stay at home, while hundreds of schools were shut down in Boston and New York.
New York Gov Andrew Cuomo said: “This is nothing to be trifled with. People should seriously consider staying in their homes.”
The deaths include those caused by difficult traffic conditions in Michigan, Kentucky, Indiana and Illinois.
A massive pile of salt fell on a worker at a Philadelphia storage facility, killing him. And authorities say a woman with Alzheimer’s disease froze to death after she wandered away from her rural New York home.
Forecasters say temperatures were plummeting to well below freezing, and wind chill readings could hit minus 10F (-23C).
Another wave of cold air already was blasting through the Midwest after moving down from Canada.
Outreach teams were searching streets in New York City and Boston for homeless people at risk of freezing to death.
Meanwhile, 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.