More than 20 states are seeing dangerously hot temperatures this week, impacting nearly 100 million Americans, according to the National Weather Service.
The heat index will be over 100 degrees from the Plains to the Southeast with little relief at night.
An excessive heat warning has been issued from southern inland California to Arizona. Temperatures in this region could reach 110 degrees over the next few days.
Record temperatures also continue in the Midwest, South and the Carolinas.
In Nashville, the recorded high was 97 degrees on Tuesday. In Fayetteville, North Carolina, the mercury hit 100 degrees.
Chicago on Tuesday experienced its warmest weather since 2012, with temps reaching 98 degrees.
MORE: Heat wave continues in 27 states across the countryThe temperature stayed at and above 80 degrees for 48 hours in Kansas City.
If the temperature in Detroit reaches 97 degrees on Wednesday, it will be the hottest recorded June temperature in the city since 2012.
Other cities seeing high temps are Charleston, Columbus and Pittsburgh as the heat wave continues to creep east.
A red flag warning continues in Nevada, where dry conditions and extreme heat perpetuates the opportunity for wildfires.
The National Weather Service said much of the Midwest will continue to remain above normal temperatures into the end of the week.
Such heat is dangerous and abnormal for even the hottest regions in the country.
MORE: Extreme heat safety tips: What to know about heat stroke vs. heat exhaustionAs the heat wave continues, schools are shutting down to protect students and staff.
Five school districts in southeast Michigan are canceling classes or adjusting dismissal times as the Detroit area braces for Wednesday’s heat.
David Mustonen, director of communications and marketing for Dearborn Public Schools in Michigan, told ABC News the district will be closed for Wednesday. He said the decision to close was necessary.
“It really had to do with the heat index being so high,” Mustonen said. “It’s just not the best condition for learning.”
Mustonen said the district’s protocol is to close if the heat index reaches 105, which will likely happen on Wednesday.
“For the students and our staff, this was just the right decision,” Mustonen added.
Schools in other metropolitan areas are adjusting their schedules amid the heat.
Pittsburgh Public Schools will only be open for half days on Wednesday and Thursday, according to the district’s website. School lunches will still be provided at Pittsburgh Public Schools during the half days.
MORE: More than 60 million in US experiencing temperatures over 100 degreesThe American Heart Association has warned that temperatures over 100 degrees can be dangerous; high temperatures cause dehydration and increase stress on the heart.
The association recommends that individuals stay hydrated, avoid caffeinated or alcoholic beverages and avoid the outdoors during the peak sun hours of about 12 p.m. to 3 p.m.