22 states hit with extreme heat warnings – stay inside

Extreme heat advisories are in place across 22 states, with the National Weather Service (NWS) warning that heat index values—which indicate “feels-like” temperatures—could climb as high as 112 degrees in parts of the South and Gulf Coast, triggering stay inside, out of the sun, warnings from the NWS.

The warnings stretch from Alaska to the Carolinas, covering parts of the Plains, Midwest, South, Mountain West and Southeast.

The affected states are:

• Alaska
• Arkansas
• Colorado
• Idaho
• Illinois
• Iowa
• Kansas
• Kentucky
• Louisiana
• Minnesota
• Mississippi
• Missouri
• Nebraska
• North Carolina
• North Dakota
• Oklahoma
• Oregon
• South Carolina
• South Dakota
• Tennessee
• Wisconsin
• Wyoming

The NWS says a “Heat Advisory” is issued when “dangerous heat conditions” are expected.

Where Heat Alerts Are in Effect

Alaska

Heat advisories are in place for parts of interior and northern Alaska, including the Western Arctic Plains, Central Arctic Plains, Yukon Flats and Fortymile Country.

Cities and areas mentioned include Umiat, Franklin Bluffs, Fort Yukon, Circle, Eagle and Chicken. Temperatures are forecast to reach 80 degrees in the Arctic Plains, 85 to 90 degrees in the Yukon Flats and up to 85 degrees in Fortymile Country.

The advisories are in effect on Monday, generally running through Sunday until Monday evening.

Arkansas

Several Arkansas counties are under heat advisories, including areas around Little Rock, North Little Rock, Conway, Searcy, Stuttgart, Dumas, Russellville, Benton and Fort Smith.

Heat index values could reach 109 degrees in central, eastern, north-central and southeast Arkansas, with other advisories covering northwest and west-central Arkansas.

Most alerts are in effect until Sunday night, while some Mississippi Valley areas remain under advisories until Monday evening.

Colorado

In Colorado, the advisory covers the Denver metro, Fort Collins, Boulder, Greeley, Lakewood, Aurora, Longmont and Highlands Ranch. High temperatures are expected to reach 98 to 102 degrees on Sunday and Monday, with warm overnight lows in parts of the Denver area.

Idaho

Heat advisories are in effect for parts of southern Idaho, including Twin Falls, Burley, Rupert, Shoshone, Boise, Nampa, Caldwell, Council and the Magic Valley. Forecast highs range from 95 to 103 degrees, depending on location.

The advisories are generally in effect until Monday night.

Illinois

Illinois counties under advisories include areas in the southern and southwestern parts of the state, including Madison, St. Clair, Monroe, Randolph, Clinton, Washington, Jefferson, Perry, Franklin, Jackson, Williamson, Saline and Gallatin counties. Cities mentioned include Belleville, Alton, Edwardsville, Sparta, Carbondale, Mount Vernon and Harrisburg.

Heat index values are expected to reach 100 to 105 degrees, with advisories lasting until Tuesday night in some areas.

Iowa

In Iowa, the advisory covers parts of western and southwest Iowa, including Council Bluffs, Red Oak, Glenwood, Clarinda, Shenandoah, Onawa, Harlan and Sidney. Heat index values of 105 to 110 degrees are expected. The advisory is in effect until late on Monday night.

Kansas

Kansas is one of the most widely affected states, with alerts covering counties in the north, east, southeast and west of the state. Cities mentioned include Topeka, Lawrence, Manhattan, Emporia, Ottawa, Fort Scott, Pittsburg, Parsons, Coffeyville, Colby, Norton, Hoxie and Hill City.

Heat index values are expected to reach 110 degrees in some areas.

Most Kansas advisories are in effect on Monday, while an Extreme Heat Watch is also in place for parts of southeast Kansas from Tuesday afternoon through Tuesday evening.

Kentucky

Western Kentucky is under a heat advisory, including Paducah, Hopkinsville, Murray, Mayfield, Madisonville, Princeton, Cadiz, and Eddyville.

Heat index values of 100 to 105 degrees are expected, with higher humidity on Tuesday potentially pushing values toward 110 degrees.

Louisiana

Heat advisories cover parts of northeast, southeast and south Louisiana, including Baton Rouge, New Orleans, Hammond, Houma, Thibodaux, Slidell, Bogalusa, Gonzales, Plaquemine, Vidalia, Tallulah and Lake Providence. Heat index values could exceed 105 degrees in some northern areas and reach up to 112 degrees in southeast Louisiana.

Advisories are in effect through Sunday evening in the New Orleans area and until Monday night in parts of northeast Louisiana.

Minnesota

Northern and central Minnesota locations under advisory include Duluth, Brainerd, International Falls, Grand Rapids, Hibbing, Ely, Pine City and Aitkin.

Heat index values up to 95 degrees are expected. The advisory is in effect from Sunday night.

Mississippi

Mississippi is under multiple heat advisories, covering areas including Jackson, Hattiesburg, Laurel, Natchez, Vicksburg, Greenville, Greenwood, Biloxi, Gulfport, Pascagoula, McComb, Picayune, Wiggins, Lucedale and Waynesboro. Heat index values could exceed 105 degrees, reach 108 degrees in southern counties, and climb as high as 112 degrees along parts of the Gulf Coast region.

Some advisories last until Sunday evening, while others remain in effect until Monday night.

Missouri

Large parts of Missouri are affected, including St. Louis, Kansas City, Springfield, Jefferson City, Columbia, Joplin, Poplar Bluff, Cape Girardeau, Sedalia, Branson and Rolla.

Heat index values are forecast between 100 and 108 degrees, with some advisories running until Tuesday.

Nebraska

Nebraska is widely covered by heat advisories, including Omaha, Lincoln, North Platte, Grand Island, Kearney, Scottsbluff, Chadron, Valentine, McCook, Alliance, Norfolk and Columbus.

Heat index values could reach 105 to 110 degrees in parts of the state, and although the advisories vary by area, many will be in effect until Monday evening.

North Carolina

Heat advisories are in place for much of eastern, central and southeastern North Carolina, including Raleigh, Durham, Fayetteville, Greenville, New Bern, Jacksonville, Wilmington, Lumberton, Goldsboro, Kinston and Morehead City.

Heat index values are expected to reach 107 to 109 degrees, with some coastal areas briefly exceeding 110 degrees. The advisories will generally run until Sunday.

North Dakota

North Dakota alerts cover central, southwest and south-central areas, including Bismarck, Dickinson, Jamestown, Carrington, Garrison, Harvey, Mandan, Hazen, Beulah and Watford City. Heat index values around 100 degrees are expected until Sunday evening.

Oklahoma

In Oklahoma, affected areas include Tulsa, Bartlesville, Miami, Claremore, Muskogee, Okmulgee, Okemah, Sallisaw, Stigler and Checotah. Heat index values up to 106 degrees are forecast through Sunday.

Oregon

The Oregon advisory covers Malheur County and the Oregon Lower Treasure Valley, including Ontario and Nyssa.

Temperatures up to 103 degrees are expected until Monday night.

South Carolina

Northeast South Carolina is under a heat advisory, including Myrtle Beach, North Myrtle Beach, Conway, Dillon, Marion, Darlington, Hartsville, Bennettsville and Loris.

Heat index values up to 108 degrees are expected, lasting until Sunday night.

South Dakota

South Dakota advisories cover a broad area, including Pierre, Aberdeen, Huron, Mitchell, Yankton, Rapid City, Winner, Mobridge, Chamberlain, Sturgis, Pine Ridge and Belle Fourche.

Heat index values are expected to range from 95 to 105 degrees, depending on the region, and are expected to last until Sunday evening, or in some cases until Monday night.

Tennessee

West Tennessee is affected, including Memphis, Germantown, Bartlett, Dyersburg, Union City, Paris, Covington, Brownsville, Somerville and Tiptonville.

Heat index values could reach 107 to 108 degrees until Sunday night.

Wisconsin

Advisories in Wisconsin cover northwest counties including Ashland, Bayfield, Burnett, Douglas, Sawyer and Washburn, with cities including Superior, Ashland, Hayward, Bayfield, Spooner and Grantsburg.

Heat index values up to 95 degrees are expected to last until Sunday evening.

Wyoming

Wyoming advisories include northeast and eastern areas such as Gillette, Newcastle, Moorcroft, Hulett, Douglas, Glenrock, Lusk, Torrington and Sundance-area communities.

Temperatures are expected in the upper 90s to low 100s, with some heat index values in surrounding advisory areas reaching 95 to 105 degrees.

Advisories are running through Sunday evening in some areas and until Monday night in others.

Why Extreme Heat Is Dangerous

Extreme heat can overwhelm the body’s ability to cool itself. Heat.gov says heat-related illness occurs when the body cannot cool down properly; body temperature can rise quickly and damage the brain and other vital organs. Heat exhaustion symptoms can include dizziness, thirst, heavy sweating, nausea and weakness, while heat stroke is a life-threatening emergency marked by confusion, dizziness or unconsciousness.

The danger is heightened when humidity is high because sweat does not evaporate as efficiently, making it harder for the body to cool itself. The NWS says the heat index measures how hot it feels when humidity is factored in, and full sunshine can make heat index values feel up to 15 degrees hotter.

Officials also warn that people trying to cool off in rivers, lakes, reservoirs, or other open water can face a separate risk: cold water shock. Even during hot weather, water can remain dangerously cold. Sudden immersion can trigger gasping, rapid breathing and loss of swimming ability, increasing the risk of drowning.

The NWS advises people to use supervised swimming locations where possible and, if in trouble, to float on their back until the initial shock passes.

What To Do During the Heat

The NWS advice repeated across the advisories is clear: drink plenty of fluids, stay inside in an air-conditioned room, stay out of the sun, and check on relatives and neighbors. People working outside should take frequent rest breaks in shaded or air-conditioned environments, and anyone overcome by heat should be moved to a cool, shaded location.

The NWS also warns that heat stroke is an emergency and says people should call 911 if someone shows signs of the condition. Young children and pets should never be left in unattended vehicles, as car interiors can reach lethal temperatures within minutes.

Contact Newsweek editors on this story: Tobias Meyjes and Tony Phillips