'Cool Routes' finds cooler walking paths with hourly forecasts and street-level shade data

[erronis]

https://phys.org/news/2026-06-cool-routes-cooler-paths-hourly.html
Arizona State University

To validate the predicted heat loads, researchers used MaRTy, a rolling instrument station that measures human thermal exposure and other meteorological data. Credit: Ariane Middel/Arizona State University

The Arizona sunshine hits like a blowtorch. The pavement radiates heat like a stove burner. To make hot-weather walking less of an ordeal, Arizona State University researchers have created a web-based app that finds the coolest, shadiest ways to reach destinations on foot.

Cool Routes, the online tool developed by Ariane Middel and colleagues in The SHaDE Lab at ASU, chooses paths based on forecasts of mean radiant temperature, a measure of the total heat load experienced in a given location, including reflected heat and sun exposure.

"It's more comprehensive than just using air temperature or land surface temperature," said Middel, an associate professor in The GAME School at ASU.

In sun-blasted Phoenix, the mean radiant temperature can exceed 150 degrees Fahrenheit in full sun but drop below 100 degrees Fahrenheit in the shade. Shade can make a real difference in people's heat exposure on a hot, sunny day. Cool Routes updates itself with hourly meteorological forecasts and works with detailed building and tree data to compute sun exposure and location-specific mean radiant temperatures on a map.

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I've spent a lot of time working in Phoenix where it is a mad dash from one AC place to another (when possible.) This sound like a good idea.