A large atmospheric heat dome is intensifying across the central and southern United States, delivering dangerously high temperatures and humidity to tens of millions of residents, according to meteorological agencies. Daytime highs have surged into the triple digits across the Southwest, southern Plains, Midwest, and Great Plains. In Denver, Colorado, authorities have implemented emergency measures, including cooling pools and systems for zoo animals and air-conditioned public cooling zones at municipal recreation centers for residents without adequate home cooling. In Indiana, organizers of the upcoming Brickyard 400 at Indianapolis Motor Speedway are adding water refill stations, misting areas, and cooling zones to protect spectators.

Prepared by Olivia Bennett and reviewed by editorial team.