Almost 3 million customers remained without power early Wednesday in Texas, Louisiana and MS, more than 200,000 more in four Appalachian states, and almost that many in the Pacific Northwest, according to poweroutage.us, which tracks utility outage reports.
Winter weather that has overwhelmed power grids unprepared for climate change and left millions in USA without electricity in record-breaking cold kept its grip on the nation's midsection on Wednesday.
"There's really no letup to some of the misery people are feeling across that area", said Bob Oravec, lead forecaster with the National Weather Service.
More than 400,000 additional doses due in Texas now won't arrive until at least Wednesday, officials said.
More than 20 storm-related deaths have been reported in the United States since the cold weather arrived last week, a lot of them in traffic accidents.
Six inches of snow have been recorded in Austin, the most in more than 70 years.
Power companies in Texas have implemented rolling blackouts to avoid grids being overloaded as residents crank up the heat.
But he added that as of midnight, 6,000 megawatts - enough to provide power to about 1.2 million homes, he said - have been added to the grid, and he said thousands of more megawatts were likely to be added soon. "Let us get the power back on", CEO Bill Magness of ERCOT, the power utility that supplies most of Texas, told CBS News.
In Houston on Monday, a homeless man was killed "possibly from exposure", according to the Harris County Sheriff's Department, and the city's police chief said another man had been found dead after potential exposure to low temperatures.
Beto O'Rourke, a former Democratic presidential candidate from Texas, told MSNBC television the situation in the "Lone Star State" was "worse than you are hearing". "They're suffering", he said.
"I'm telling my community do not expect the power to come back even after the weather passes", Hidalgo said on CNN.
According to the Poweroutage.us tracking site, more than three million residential, commercial and industrial customers were without electricity in Texas as of Tuesday evening.
Austin Energy, the local power company, said almost 200,000 area customers were without electricity. While the storm was the "central cause" of the power outages, he said there were outages caused by generation of coal and natural gas, as well as wind and solar, he said. The unusual winter weather created a huge demand for electricity that caused the state's independently-run power system to fail, exposing issues with its structure.
The weather has also put a crimp on the national COVID-19 vaccination drive.
"What we're encouraging governors and other partners to do is to extend hours once they're able to reopen".
Many weather-related deaths so far have resulted from traffic accidents, but Houston police said a woman and a girl died from carbon monoxide poisoning after sitting in a auto in a garage with the engine running to keep warm.
More than 2.5 million Texas power customers remain in the dark after unprecedented winter storms froze several of the state's power sources. Some of the fatalities involve people dying in their cars in subfreezing temperatures.
Two agricultural workers died in neighboring Tamaulipas from hypothermia.