Utility crews braved sweltering heat Sunday in an attempt to restore power to millions of people in the eastern United States after powerful and deadly storms swept through the region Friday.

Not only are millions without basic conveniences like refrigeration and air conditioning, they're battling a second day of 38 C temperatures.

People flocked to malls and movie theatres that had power, hoping that by the time they returned home, electricity would be restored.

But it could be several days, or even a week, before power is back on for most homes and businesses as crews work their way through tangled wires and downed trees.

The storms Friday were so powerful they toppled massive trees onto cars, blocked roads and brought down huge electricity towers, with emergency staff having little or no time to prepare for their unexpected ferocity.

“Unlike a polite hurricane that gives you three days of warning, this storm gave us all the impact of a hurricane without any of the warning of a hurricane,” Maryland Gov. Martin O'Malley said.

Most of the storm damage was in West Virginia, Washington and the capital’s Virginia and Maryland suburbs.

The death toll reached 17 late Sunday, after officials in eastern North Carolina said sudden storms in the region left three people dead.

At least seven people died in Virginia, including a 90-year-old woman asleep in her bed when a tree slammed into her home.

Two young cousins in New Jersey were killed when a tree fell on their tent while camping. Two were killed in Maryland, one in Ohio, one in Kentucky and one in Washington.

Washington’s northern Virginia suburbs even lost their emergency 911 call centres with residents being asked to call local police and fire departments.

Cell phone and Internet service was spotty, gas stations shut down and residents were urged to conserve water.

But a major concern is that the storms left many parts of the region without air conditioning in the extreme heat.

Those temperatures continued throughout Saturday and Sunday.

“If we don't get power tonight, we'll have to throw everything away,” Susan Fritz, a mother of three, said about her refrigerator and deep freezer.

Fritz stopped by a library in Bethesda, Md., for her son to complete his online classwork.

She said her eldest son was also unable to work as a lifeguard because the local pool complex had no electricity.

New Jersey Gov. Chris Christie ordered the National Guard to deliver fuel for generators and fresh water to stricken areas.

He also said power had been restored to such tourist areas as Atlantic City's casinos.

But officials were focusing on the most vulnerable residents: children, the sick and the elderly.

In Charleston, W.Va., firefighters helped several people using walkers and wheelchairs get to emergency shelters.

In the Columbus, Ohio, suburb of Dublin, Lori Schaffert said she borrowed a generator from a friend and was alternating it between the refrigerator and freezer while using flashlights and battery-operated lanterns for light.

“You come to appreciate the simple life a little more in these times,” Schaffert said.