This article was originally published by Grist and is reproduced here as part of the Climate Desk collaboration.

A jogger runs along the shoreline of Lake Michigan, with heavy smoke from the Canadian wildfires in the background, in June 2023. Kamil Krzaczynski / AFP via Getty Images via Grist

As extreme heat worsens pollution, a network of 277 monitors will identify pollution hot spots.

Serap Erdal stopped at a light pole in Chicago’s Grant Park, pulled out her phone, and began pinching at the screen. Behind her, towering skyscrapers cut into a sunny blue sky as she scanned her palm-sized map of the city. The researcher barely noticed the hum of city buses, cars, and cyclists buzzing around her in the city’s busy downtown. She was working out what was in the cool summer air.

Fixed to the pole above her was one of the city’s new solar-powered air quality monitors.…