More than 106 million Americans from the Upper Midwest to the Gulf Coast are under various heat alerts on Wednesday as a relentless heat dome refuses to release its fiery grip on the central U.S.
Of those on heat alert, nearly 69 million are under Excessive Heat Warnings from Minneapolis and Chicago to New Orleans and the Florida Panhandle.
"It's expected to be the hottest week so far in America," said Meteorologist Bob Van Dillen.
And, according to the Weather Prediction Center, the oppressive heat in the Midwest will pose a greater health risk than usual - and potentially be deadly - due to the multiple consecutive days of extreme heat, the intensity of the heat and the lack of cooling overnight.
"Heat of this intensity will pose a health risk to anyone without effective cooling and/or adequate hydration," the WPC warned. "Do not underestimate the potential for heat-related illness."
Dangerous heat forces evacuations at Kansas City nursing home
The Kansas City Fire Department transported 117 people from a nursing home in the city after an HVAC failure.
Officials say they had to transport the individuals due to the unbearable heat.
Kansas City is seeing high temperatures in the triple digits, with heat indices near 115.
Schools close from lack of air conditioning amid dangerous heat
"People are kind of sleeping on the fact that this is the hottest week of the year likely for places where it's already been a hot summer," said Meteorologist Ian Oliver.
Some meteorologists have taken to social media saying that parts of the Midwest through the South could see some all-time record high temperatures.
The Milwaukee Public School district announced Tuesday afternoon that schools will be closed Wednesday because the buildings are not air-conditioned.
But high temperatures don't tell the entire story. When the humidity is factored in, the feels-like temperature or heat index soars.
Kansas City will feel like 100 degrees and 104 degrees on Wednesday and Thursday, with Chicago getting in on the heat as well with forecast high temperatures approaching 100 degrees today and tomorrow. The feels-like temperature in Chicago hit 112 degrees on Wednesday afternoon, marking the last time the heat index was higher than 112 since it reached 114 degrees in 1999, according to the National Weather Service.
Farther south, Baton Rouge, Louisiana, will see a forecast high temperature above 100 degrees through the first part of the weekend.
Agricultural areas will have added humidity from crops and evapotranspiration or "corn sweat." Crops sweat to cool down, just like humans, and provide extra moisture to the air.
Heat dome not budging
The area of high pressure anchoring the heat dome over the middle of the country hasn't budged for most of the summer.
"That high pressure actually builds up in strength and thickness, which means you're going to see more of these records going down," said Van Dillen.
By Thursday, more than 182 million people will endure highs of 90 and above.
The hot and humid combination spells out dangerous daytime heat. Unfortunately, heat illness is cumulative, so the sultry nights won't give much opportunity to cool down and repair. The greatest risk of excessive heat is through eastern Texas and parts of the Gulf Coast States, according to the FOX Forecast Center.
"Portions of the South Central U.S. and Gulf Coast may further extend their record number of days with a heat index reading of at least 110," said the FOX Forecast Center.