Millions endure record cold without power in US

At least 13 children were treated for carbon monoxide poisoning at Cook Children's Medical Center in Fort Worth, the hospital said in a social media post, which warned that families were "going to extreme measures to warm their homes" with propane or diesel-burning engines and generators as well as gas ovens and stovetops.

One parent died of the toxic fumes, pediatrician Phillip Scott told Fort Worth television station KTVT.

Other Texas deaths included a woman and a girl who died from suspected carbon monoxide poisoning in Houston at a home without electricity from a car left running in an attached garage, and two men found along Houston-area roadways who likely died in subfreezing temperatures, law enforcement officials said.

In west Tennessee, a 10-year-old boy died after falling into an ice-covered pond on Sunday during a winter storm, fire officials said.

Several cities had record lows: In Minnesota, the Hibbing/Chisholm weather station registered minus 38 degrees Fahrenheit (minus 39 degrees Celsius). Sioux Falls, South Dakota, dropped to minus 26 Fahrenheit (minus 26 degrees Celsius).

Air travel was also affected. At midday, more than 2,700 US flights had been canceled, led by more than 800 at Dallas Fort Worth International Airport and more than 700 at Bush Intercontinental in Houston.

Authorities pleaded with residents to stay home Tuesday.

About 100 school systems closed, delayed opening or switched to remote classes in Alabama, where forecasters said conditions might not improve until temperatures rise above freezing Wednesday afternoon.

--AP