A winter storm dropped 13.5 inches of snow on Philadelphia Tuesday and a deep freeze, that may last as long as three weeks moved in Wednesday, the Philadelphia Inquirer reported.
Three deaths due to the cold were reported in Delaware County.
In Ridley Township, two elderly people -- an 89-year-old man and a 93-year-old woman -- were found dead outside in separate parts of the town Wednesday morning, police said. The deaths were related to the freezing temperatures, police said.
A 67-year-old man died at a hospital in Swarthmore after being found unresponsive by his wife outside their home. That death was also believed to be cold-related.
In the greater Northeast, forecasters said temperatures, which are currently about 30 degrees below average, will remain low for at least the next week, NBC News reported.
"In a lot of the Northeast, the highs will be in single digits and we're expecting those to continue possibly through Friday," said Michael Palmer, a meteorologist with the Weather Channel. "Our advice would be to wrap up warm."
Small snow storms are also possible, meteorologists said.
Meanwhile, in Chicago, a deep freeze will last into at least next week, with the warmest temperatures coming on Friday, the Chicago Tribune/WGN-TV reported Thursday.
"By warmer, we're just calling for mid-20s for highs," said Kevin Birk, a meteorologist with the weather service.
Temperatures may not reach zero by Monday, and wind chills may reach 30 or 40 below, Birk said.
"Really," Birk said, "there is no foreseeable end to the deep cold here."
The National Weather Service warned that "frostbite and hypothermia can occur in a matter of minutes" in such extreme temperatures.
Parts of Texas are also experiencing low temperatures, NBC said. Houston and San Antonio were expecting ice by Thursday night.
Winter-storm watches and winter-weather advisories have been issued for those areas, were temperatures will be in the 20s, Palmer said. Parts of the Rockies and southern Louisiana will also experience the cold front.