Extreme weather gripped large parts of the Southern United States on Monday, with several governors declaring states of emergency and officials in Texas urging residents to conserve energy.

Hazardous driving conditions hit highways in states ill-equipped to deal with icy and snowy roads, and Alabama, Kentucky and Mississippi issued states of emergency. Luckily, many offices were closed for Martin Luther King’s Birthday.

In Texas, a message issued by Gov. Greg Abbott painted a worrisome picture, warning that much of the state is expected to face temperatures below freezing for “dozens of hours” this week.

Wind chills below zero were anticipated across much of the northern half of the state Monday, according to the advisory. Just three years ago a storm killed 246 people and knocked out electricity for millions.

Officials have since moved to shore up the power system. Even so, the state’s Electric Reliability Council issued an appeal, asking Texans to conserve power Monday morning by avoiding the use of large appliances and turning off lights.

At Dallas-Fort Worth International Airport, which marked its 50th anniversary over the weekend, delays and cancellations piled up as temperatures plummeted to the low teens and blasts of wind whipped snow across the runways.