The mercury was plummeting across the US Midwest on Saturday as a biting winter storm left hundreds of thousands without power and threatened to disrupt the first key event in the 2024 presidential election campaign.
Over a quarter of a million people in Michigan and Wisconsin were left without power as freezing temperatures spread across the region, according to PowerOutage.US website.
Winds and heavy snow also grounded planes at Chicago's O'Hare International Airport with some 7,600 flights delayed across the country.
States of emergency were declared from New York to Louisiana with the National Weather Service in St Louis warning of a "life-threatening" cold.
Extreme winter weather
"EVERY state in the US has an active NWS watch, warning, or advisory," the National Weather Service said on Friday.
These ranged from the blizzards announced for Iowa, Wisconsin and Michigan, to avalanche warnings in Utah, Wyoming and Idaho, and from coastal flooding warnings in both the east and west, to winter storm warnings or winter weather advisories covering much of the rest of the country.
Authorities already announced the first cold-related death of the season after a man reportedly died following exposure in suburban Chicago.
The city is expecting several inches of snow, wind gusts of up to 50 miles per hour (80 kilometers per hour) and wind chills as low as minus 15 degrees Fahrenheit (minus 26 Celsius). Such low temperatures can cause frostbite after just 15 minutes of exposure.
Dozens of homeless people, many of them migrants, were placed in "warming buses" to stop them freezing to death on the streets while they waited for space in city-run shelters.
Many of the migrants have been bused in from Texas. Illinois Governor J.B. Pritzker called on his Texan counterpart Greg Abbot to stop sending migrants north during the extreme cold weather, but Abbot has refused.
Cold start for the Republican primary
The storm also descended on Iowa where Republican presidential candidates are set to take part in the first primary vote on Monday.
Nikki Haley, Ron DeSantis and former President Donald Trump were all forced to reschedule their campaign events as blizzard warnings were declared.
Monday's vote is only the first in a state-by-state contest set to determine who will be the GOP's presidential candidate in November.
Trump has consistently led in the polls, with quite some margin, but an upset in Iowa could set the course for the rest of the primary votes.