(Updated at 12:00 p.m.)

The White House on Thursday made the obvious official: The region's epochal ice storm that darkened entire communities, shut down businesses, and turned schools into emergency shelters was, indeed, a certified disaster.

With the presidential declaration, Philadelphia and the four suburban Pennsylvania counties became eligible to apply for Federal Emergency Management Agency aid. York and Lancaster Counties also were included.

In all, 715,000 Peco Energy customers lost power as a result of the storm - the second-highest total for any one event, said Peco spokesman Ben Armstrong. Hurricane Sandy darkened 850,000 customers in 2012.

Along with the outages, storm-felled trees and branches continued to disrupt traffic, and knocked SEPTA's busy Paoli-Thorndale Line all day Thursday. Service was restored by Friday morning's commute.

Peco said that most customers should have their lights and heat back by Friday night, but some might remain off-line until Sunday. Meanwhile, forecasters said nature won't provide much comfort; it will remain cold, with light snow possible on the weekend.

On a day when the temperatures struggled to get out of the 20s, storm victims on Thursday sought refuge from their refrigerated homes in pizza shops, malls, schools, and "warming centers."

In a visit to survey damage in the Blue Bell section of Whitpain Township, Montgomery County, Gov. Corbett said that National Guard troops were on standby, and that some had been enlisted to help residents dig out or get their cars moving.

Corbett toured some of the fallen trees and power lines Thursday elsewhere in the township, near Skippack Pike, where Peco crews were working to restore a high-voltage line that served thousands of homes.

Neighbors shivering through their second outage of the week stood outside in pajama pants, boots and heavy coats, waiting to hear the governor.

Nina Brooks said that with a 4-year-old and a 7-year-old in the house, the family couldn't hold out much longer.

"It was an adventure, and we made the best of it last night. But it's a little crazy, getting like cabin fever," she said.

In Chester County, Phoenixville Fire Chief John Buckwalter said this has been the longest outage in the borough in at least 20 years.

Corbett urged residents to be patient as more than 5,000 utility workers tried to restore electricity, and urged those without power to go to shelters.

"Unless they are going to somebody's home or staying at a hotel, staying at home at this point and trying to heat with alternative sources can be dangerous," he said.

Cases in point: After using a charcoal grill to heat their home, five members of a New Garden Township, Chester County, family were taken to a hospital for treatment of carbon monoxide poisoning, emergency officials said. Their conditions were not known. And Thursday night in Horsham Township, authorities said, several people were taken ill after burning charcoal inside a residence.

All the havoc was caused by an avalanche of fallen trees and branches, overburdened by Monday's heavy snow and Wednesday's ice and rain that ripped down power lines.

"It was like bombs going off when the transformers were going out," said John Saal, a graphic designer whose Newtown Square, Delaware County, neighborhood had been without power since 4 a.m. Wednesday.

In some cases, trees fell on roads and dragged the power lines with them, creating massive traffic headaches, further compounded by the legions of not-working traffic lights.

In Exton, Pottstown Pike was backed up for at least a mile in both directions because of a disabled light at the Route 30 bypass ramps.

About 50 roads were at least partially closed in Montgomery County, which is still under a state of emergency. Trees and wires blocked all or parts of 68 state-owned roads in the suburban counties, according to the Pennsylvania Department of Transportation. Blocked side streets added to congestion on already-clogged main highways.

With chill filling their homes, many people sought refuge wherever they could find it, in coffee shops, pizzerias, and schools that had been transformed into emergency shelters. When schools will reopen is unknown.

The Fill-A-Bagel shop on Old York Road in Jenkintown was wall-to-wall Thursday morning with customers - most of whom were nearby residents looking for a hot cup of coffee and a power outlet.

Anne Cooper, 67, of Elkins Park, had been without power since Tuesday night.

"We've been using our fireplace, which wasn't great, but it was OK," she said.

Her daughter and grandson, who live in Rydal, spent most of Wednesday at the Willow Grove Park mall.

"She said it was like a war zone, people on the floor, charging their phones and computers," Cooper said.

Norman Loev, 79, returned to his home in Rydal on Wednesday after visiting his son in Southern California.

"This is what we came back to: no heat, no electricity," he said. Thursday night, he and his wife stayed with their daughter in Southampton.

The Loevs plan to flee Friday and take refuge on their sailboat in Miami. "We'll probably just drain the pipes and leave," he said.

The Neshaminy School District in Bucks County and the Phoenixville Area School District turned buildings into emergency shelters or warming centers, several of which popped up throughout the region.

In Chester County, Red Cross officials consolidated three shelters into one at West Chester University.

Amy Perrone and her daughters, Hayden, 10, and Cora, 7, went to the Barkley Elementary School shelter in Phoenixville after trying to share one bedroom with a portable heater.

"We finally just decided, 'OK, enough is enough,' " Perrone said. "We get a little crazy, being in one room."

Sarah Dise, 25, of Exton, arrived about 8:30 p.m. Wednesday after a friend gave her the county's emergency number and told her to call for a ride to the shelter. She said Thursday she had a "rough night" and was unable to fall asleep after waking at 2 a.m.

"I didn't sleep much because I was afraid to be here, scared of being with people I didn't know," she said. "But they made me feel comfortable."

Contributing to this article were staff writers Michaelle Bond, Carolyn Davis, Robert Moran, Clark Mindock, Tricia L. Nadolny, Jessica Parks, and Chris Palmer.