(CNN) — Dangerously hot temperatures will spread into the South Tuesday, adding to a miserable heat wave that has caused at least one death in the Midwest.
While the combination of heat and humidity will send the heat index — a measure of how hot it feels — deep into the triple digits in parts of the South Tuesday, Oklahoma City, Oklahoma, will endure its 14th straight day with temperatures alone above 100, National Weather Service spokesman Chris Vaccaro said.
And it will stay that way until next week.
The National Weather Service issued a heat advisory for parts of 24 states and the District of Columbia, with parts of 10 Midwestern and Southern states getting a more extreme excessive heat warning as well.
The areas covered by the excessive heat advisory — parts of Oklahoma, Kansas, Missouri, Arkansas, Illinois, Indiana, Kentucky, Tennessee, Mississippi and Alabama — can expect the heat index to rise above 110 degrees Tuesday, the Weather Service said.
The hottest of the hot looks to be Mississippi and parts of Tennessee, where forecasters warned the heat index could soar to 116.
Other states included in the heat advisory are Connecticut, Delaware, Kansas, Louisiana, Maryland, New Jersey, New York, North Carolina, Ohio, Pennsylvania, South Carolina, Texas and Virginia.
While extreme heat is forecast as far north as Connecticut — New York could see a heat index of 103 on Tuesday — the impact in that part of the country will be short-lived, Vaccaro said.
Temperatures will return to nearly normal summertime levels by Wednesday throughout the Northeast, he said.
High pressure over the Plains is keeping the weather pattern stable, allowing heat to build and expand up the Eastern Seaboard. A cooler, dryer weather system is nibbling at the northern edges of the heat wave, threatening to exchange high temperatures for potentially dangerous thunderstorms, according to forecasters.
There’s not quite so much relief in store for residents of the lower Midwest and South.
“This has been going on all weekend and will continue into this week,” Vaccaro said.
In Oklahoma City, forecasters are calling for nearly another full week of temperatures above 100 degrees, threatening to break a 1936 record for 22 consecutive days of such heat.
And nighttime will bring little solace.
While record- and near-record daytime highs are being set, many areas are also experiencing record warm lows at night. For instance, the low temperature of 83 recorded early Tuesday in North Little Rock, Arkansas, set a new record for the warmest low in July, Vaccaro said.
Warm nights are a problem for people without air conditioning, he said.
“If you’re exposed to the outside elements, your body can’t cool down at night,” he said.
The heat has already claimed at least one victim, a 51-year-old man in Granite City, Illinois, who died Sunday due to the excessive heat, according to the Madison County coroner.
Mitsunari Uechi was found unresponsive in his mobile home, where the air conditioning was not working. Police described the residence as “extremely hot,” Coroner Stephen Nonn said in a statement.
Uechi was transported to Gateway Regional Medical Center with a body temperature of 104 degrees. He was later pronounced dead, according to the coroner.
Nonn noted that Uechi “suffered from chronic medical problems that placed him in a higher risk for heat-stress related illness.”
Stillwater, Oklahoma, and Fort Smith, Arkansas, notched Monday’s high temperatures across the United States, topping at 107 degrees, the weather service said. At least a dozen cities hit the century mark, with many others well into the 90s.
Several high-temperature records have been broken recently.
Wichita, Kansas, hit 111 degrees Sunday. The National Weather Service says temperatures of 111 degrees have occurred there only 10 times since July 1888.
Forecasters say people should limit outdoor activity during the hottest portions of the day, wear lightweight clothing, drink plenty of water and be watchful for signs of heat exhaustion, which include heavy sweating, pale and clammy skin, weak pulse, fainting and vomiting.
CNN’s Monica O’Connor, Meteorologist Jacqui Jeras and Ed Payne contributed to this report.
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