Extreme heat warnings were issued for 14 states on Sunday, complicating an already dangerous situation created by a massive weekend storm that killed at least 12 people and left more than 3 million without power in the mid-Atlantic.
The National Weather Service forecast excessive heat from Illinois to Georgia, a day after a deadly "derecho"--or fast-moving "straight-line" of high winds--ripped through the nation's midsection, while record triple-digit temperatures throttled several major cities. Atlanta hit 106 degrees on Saturday, one of more than 1,500 U.S. temperature records broken last week.
"It is very unsafe outdoors for those susceptible to these extreme conditions," the weather service warned. The heat combined with moderate humidity will result in heat indices topping 115 degrees.
[Slideshow: Photos of the devastation]
"I'm very concerned with the problems created by the combination of power outages and severe heat," Ohio Gov. John Kasich said. Close to a million people were without power in Ohio late Saturday, and Kasich said it could take up to a week to restore power in some areas.
President Obama authorized the Federal Emergency Management Agency, or FEMA, to coordinate disaster relief in Ohio, according to Reuters. States of emergency have been declared in Ohio, Maryland, Washington, D.C., Virginia and West Virginia, where 232 Amtrak passengers were stranded for more than 20 hours after trees fell across the tracks on both sides of the Chicago-bound train.
"This is not a one-day situation," Virginia Gov. Bob McDonnell said. "It is a multi-day challenge."
According to the Associated Press, it could be a week before electricity is restored in the D.C. metro area, where more than 400,000 were without power.
"We do understand the hardship that this brings, especially with the heat as intense at is," Pepco spokeswoman Myra Oppel told the AP. "We will be working around the clock until we get the last customer on."
In Baltimore, three fire departments that were set to close will remain open to assist with the clean-up. In Illinois, 78 inmates were transferred from a prison that sustained significant damage.
For those with power, "some major online services also saw delays and disruptions," the AP reported. "Netflix, Instagram and Pinterest resorted to using Twitter and Facebook to update subscribers after violent storms across the eastern U.S. caused server outages for hours."
Netflix and Pinterest restored service by Saturday afternoon, the AP said.
As is custom in the age of social media, Twitter, Facebook and Flickr users posted dramatic photos of the storm and its aftermath.