(NBC News) Much of the nation suffered through another day of scorching temperatures Thursday.
The dangerous heat has lingered for days, prompting warnings from doctors.
"Those who cannot protect themselves from heat, like the very young or the very old. Those are the people who are the most common victims of heat," warns Dr. Bill Frohna of MedStar Washington Hospital Center.
The heat is coming from a large "dome" of high pressure in the upper atmosphere that's located over the Ohio Valley, Great Lakes and Northeast, and is expected to last for at least a few more days.
-- Chris Clackum, NBC News, reports