President Joe Biden has ordered federal assistance to supplement local response efforts following extreme cold weather

The Arctic blast has seen temperatures drop across most of Texas to their lowest point in 30 years, but some areas have experienced the coldest weather in more than a century.
Amarillo will see a high temperature of just -17C, breaking the city’s previous record of -11C that was set in 1895, a forecaster from the service’s Weather Prediction Centre, Marc Chenard, told Reuters news agency.
The weather alo caused the largest oil refinery in the US to shut down its operations. Motiva Enterprises said unprecedented freezing temperatures necessitated safely and methodically shutting down the oil refinery located in Port Arthur, Texas, which processes more than 600,000 barrels a day.
But the cold temperatures are not just affecting Texas. 
Much of the United States has been shivering under chilly temperatures for days, with only parts of the southeast and southwest dodging it.
Nearly 170 million people are now under winter weather advisories and there are emergency declarations in at least seven states, including Alabama, Oregon, Oklahoma, Kansas, Kentucky, Mississippi and Texas.