(CNN) Extreme heat is forecast again for a large swath of the US on Wednesday, testing power grids and leaving nearly 100 million people from Michigan to northern Florida under heat warnings and advisories. "AEP is dealing with the damage from last night's storms plus high demand because of excessive heat. Both the Tennessee Valley Authority and Texas operator ERCOT recorded highs for electricity usageSchools have been forced to alter schedules due to the excessive heat. Detroit Public Schools announced they will close all in-person schools three hours early through Friday due to the extreme heat. An excessive heat warning has also been issued for parts of interior southern California and Arizona, where daytime highs are expected to soar once again well into the triple digits.

Source: CNN June 15, 2022 13:35 UTC