Utilities from Minnesota to Texas and MS have implemented rolling blackouts to ease the burden on power grids straining to meet extreme demand for heat and electricity as record low temperatures were reported in city after city.
The slow thaw and more frigid lows ahead was also taking a toll on Texas' distribution of Covid-19 vaccines. Oklahoma Gas & Electric urged users to set thermostats at 68 degrees Fahrenheit (20 degrees Celsius), avoid using major electric appliances and turn off lights or appliances not in use.
The Southwest Power Pool, a group of utilities across 14 states, called for rolling outages because the supply of reserve energy had been exhausted.
Massive power outages across Houston included a facility storing 8,000 doses of Moderna vaccine, leaving health officials scrambling to find takers at the same time authorities were pleading for people to stay home.
"You know they're driving too fast".
"It feels wonderful. I'm very grateful", said Harry Golen, a college sophomore who waited for almost four hours with his friends, much of it in the cold.
Texas officials said more than 400,000 additional doses due now will not arrive until at least Wednesday because of the storm.
Three people died and 10 were injured when the tornado tore through a golf course community and another rural area just before midnight Monday, destroying dozens of homes. Resident Sharon Benson told CBS News she was shocked by the tornado, because forecasters "said it was going to rain".
Winter storm watches were in effect from Baltimore to Boston, and Texas braced for more icy rain and possibly more snow. A MS man died after losing control of his vehicle, which overtuned on an icy road Monday night near Starkville, Oktibbeha County coroner Michael Hunt said Tuesday.
Four died in Monterrey, three of them homeless people who succumbed to exposure and one person who died at home from carbon monoxide poisoning from a heater.
Despite an initial rush by fossil fuel-friendly commentators and other media sources to blame frozen wind turbines for deadly power outages in Texas, the organization that manages a vast majority of the state's power grid said that wind woes have been the least significant factor in the blackouts.
Christine Chapman, center, sets down an empty canister to exchange for a full propane tank from Robert Webster, left, outside a grocery store in Dallas, Texas, on February 16, 2021.
A man in Louisiana died when he hit his head after slipping on ice, and a 10-year-old Tennessee boy died after he and his six-year-old sister fell through the ice into a pond Sunday. In Minnesota, the Chisholm-Hibbing weather station registered -39C (-38F), while Sioux Falls, South Dakota temperatures dropped to -32C (-26F).
Authorities pleaded with residents to stay home Tuesday.
Travel remains ill-advised in much of the United States, with roadways treacherous and thousands of flights canceled.
Many school systems have delayed or cancelled face-to-face classes.