Texas remained in the frigid grip of winter storms on Wednesday as a fresh arctic blast deepened an electricity supply crisis that has forced millions to endure days without power and heat.

More than 100 million Americans are in the path of the storm as it tracks from the southern Plains to the East Coast over the next few days, the National Weather Service said.

But the nation’s heartland will get some relief over the weekend, the weather service reported, as the frigid air will begin to moderate over the next couple days.

But first, much of Texas and the Southeast will have to endure heavy snowfall and “ice accumulations of a light glaze to a few hundredths of an inch” through Thursday. Heavy snow is forecast to move work its way as far north as southern New England on Thursday.

More than 30 people have died because of the intense cold and a series of storms that moved from coast to coast since the weekend. In the Houston area, one family succumbed to carbon monoxide from car exhaust in their garage; another perished after flames spread from a fireplace.

At least 13 children were treated for carbon monoxide poisoning at Cook Children’s Medical Center in Fort Worth, Texas, hospital officials said.

In Texas, more than 1.6 million homes and businesses remained without power late Wednesday night, and some also lost water service. Texas officials ordered 7 million people — a quarter of the population of the nation’s second-largest state — to boil tap water before drinking it. All of Austin is under a water boil notice, city officials announced Wednesday night.

Texas wasn’t the only state contending with power issues. Other states where outages numbered in the tens of thousands included Louisiana, Mississippi, West Virginia, Kentucky, Virginia, Ohio and Oregon, according to poweroutage.us, a utility tracking site.