Millions of people in a swath of states along the East Coast and farther west went into a third sweltering day without power today after a round of summer storms that killed more than a dozen people.

The outages left many to contend with stifling homes and spoiled food over the weekend as temperatures approached or exceeded 38 C.

Some two million customers from North Carolina to New Jersey and as far west as Illinois were without power Monday morning. Utilities warned that many neighborhoods could remain in the dark for much of the week, if not beyond.

Since Friday, severe weather has been blamed for at least 18 deaths, most from trees falling on homes and cars.

'They kind of forgot about us out here'— resident Eric Nesson

The power outages had prompted concerns of traffic problems as commuters took to roads with darkened stoplights. But throughout northern Virginia, there was less traffic than normal in many places Monday as federal workers took advantage of liberal leave that was put in place for the day.

Some drivers resorted to ingenuity to get to work. On a residential street in suburban Falls Church, Va., just outside Washington, downed trees blocked the road on either side. Enterprising neighbours used chain saws to cut a makeshift path on one side, but the other remained completely blocked by a massive oak tree.

"They kind of forgot about us out here," resident Eric Nesson said.

Still, residents took the aggravation with good humor. Posted on the oak tree was a sign saying: "Free firewood you haul." The tree lay across a smashed Ford pickup truck, with a sign reading: "For SALE. Recently lowered."

Meanwhile, coast guard officials say they have suspended the search for a man who disappeared early Saturday while boating during the storm off Maryland.

A grocery store employee piles bags of ice for free distribution in Bethesda, Md., on Monday to help community members affected by Friday's storm. (Manuel Balce Ceneta/Associated Press)

On Sunday night in North Carolina, a 77-year-old man was killed when strong winds collapsed a Pitt County barn where he was parking an all-terrain vehicle, authorities said. In neighboring Beaufort County, a couple was killed when a tree fell on the golf cart they were driving. Officials said trees fell onto dozens of houses, and two hangars were destroyed at an airport in Beaufort County.

The damage was mostly blamed on straight-line winds, which are strong gusts pushed ahead of fast-moving thunderstorms like a wall of wind.

Elsewhere, at least six of the dead were killed 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.

In West Virginia, authorities said one person died early Sunday when the all-terrain vehicle they were riding hit a tree that had fallen over a road.

For survivors, it was a challenge to stay cool over the weekend.

Atlanta set a record with a high of 40 C, while the temperature hit 37 at Ronald Reagan Washington National Airport just outside the nation's capital.

With no air conditioning, officials urged residents to check on their elderly relatives and neighbors. It was tough to find a free pump at gas stations that did have power, and lines of cars snaked around fast-food drive-thrus.

Ontario sends help

Power restoration was spotty. Several people interviewed by The Associated Press said they remained without power even though the lights were on at neighbors' homes across the street. In Maryland, Gov. O'Malley promised he would push utility companies to get electricity restored as quickly as possible.

"No one will have his boot further up Pepco's and BGE's backsides than I will," O'Malley said Sunday afternoon, referring to the two main utilities serving Maryland.

Aid from across the border was expected from Ontario's Hydro One power utility, which has assisted in the past when natural disasters caused widespread blackouts in the U.S.

Hydro One announced Sunday that about 200 workers would be sent to the Baltimore, Virginia and Washington regions to assist in restoring electricity to affected areas.

"Hydro One crews have a long-standing history of assisting neighbouring utilities when help is needed the most, and this time is no exception," Len McMillan, Hydro One's vice-president of lines and forestry, said in a statement.

"Our crews are ready and willing to do what they do best — help restore power quickly and safely to impacted customers."

The Canadian crews are expected to get working in the affected areas as early as Tuesday.

Hydro One has a history of providing assistance to U.S. cities following significant power outages. For example, the power utility helped utilities in Vermont in February 2010 after a massive winter storm crippled power, and in 2008, crews helped out in Ohio after Hurricane Ike caused massive blackouts.

With files from CBC News