Temperatures could soar as much as 20 degrees above average, pushing heat indexes well into the triple digits.
The majority of Ohio has been under an excessive heat warning, according to NWS, and a spokesman for electric company AEP Ohio told CNN that some customers should prepare for outages to last until Thursday.
Columbus Mayor Andrew Ginther called on residents to use cooling centers and swimming pools on Wednesday to beat the heat, and to check on neighbors as power slowly comes back online.
Schools have been forced to alter schedules due to the excessive heat. In Wisconsin, where a heat index of 108 degrees Fahrenheit was recorded by NWS Tuesday at Milwaukee Mitchell International Airport, Milwaukee Public Schools dismissed students early and said it will do so again Wednesday.
“Young children and persons with certain health conditions are especially vulnerable to heat-related distress,” MPS announced on its website. “For the safety of all, the district has decided to shorten the school day.”
More than a dozen schools in Minnesota that are not fully air-conditioned moved to e-learning on Tuesday, according to Minneapolis Public Schools. Detroit Public Schools announced they will close all in-person schools three hours early through Friday due to the extreme heat.
Relief may soon arrive for the Midwest as the heat is forecast to break late Wednesday, with a cold front due to bring cooler temperatures, scattered showers and thunderstorms.
Temperatures will drop to more-average levels as the front moves through Minneapolis on Wednesday afternoon and Chicago by Wednesday overnight. The cold front is forecast to move through Ohio by Thursday.
Wildfires rage in Arizona, New Mexico
A second fire just a few miles away, the Haywire Fire, has burned roughly 4,000 acres, according to InciWeb, and both fires remain 0% contained.
Firefighters in New Mexico are battling the two largest fires in the state’s history, the Hermits Peak/Calf Canyon Fire just northeast of Santa Fe and the Black Fire in the Gila National Forest. They have burned more than 600,000 acres combined.
“More than 6,200 wildland firefighters and support personnel are assigned to incidents,” the NIFC said Tuesday.
CNN’s Robert Shackelford, Judson Jones, Theresa Waldrop, Andy Rose and Dave Alsup contributed to this report.