A Routing App to Avoid the Heat: HEAL App now available also for Worms

As summer temperatures soar, being outdoors poses rising health risks, especially in urban areas and for vulnerable groups like the elderly, children, and citizen with pre-existing conditions. The HEAL project launched a routing app to help citizens avoid heat stress, supporting climate adaptation and public health during hot weather periods. Initially developed for Heidelberg, the HEAL app is now also available in Worms.

The HEAL app: a guide to choose cooler and safer walking routes in Heidelberg and now also Worms

The HEAL app is a web-based routing application designed to facilitate heat-adapted mobility. With the app, users can calculate alternative routes that steer away from main roads with little shade, suggesting routes through parks and shaded areas instead. The app provides detailed information about the type of path, surface and gradient along the chosen route. The routes are calculated based on current heat and sun exposure conditions, customizing the routes according to the day´s weather and the time of the day.

This app aims to support mobility on hot days and raise awareness of the effects of climate change. It was developed by modeling heat conditions across the city using statistical models based on real-time sensor data (in Heidelberg only) and sun exposure models.

The web app, released for Heidelberg last summer, is now available also in Worms:

With the HEAL app, users can find out which pedestrian route is best to avoid the heat according to the time of the day and the resulting sun exposure of the path. For instance, the best path from Worms´s main train station to the Rhine promenade varies during the day: in the morning, the HEAL app suggests taking the Wilhelm-Leuschner Straße and then walking along the Martinsgasse and Judengasse, while in the afternoon, the coolest way goes through the Goethestraße. The slightly shorter route via Siegfriedstraße and Berliner Ring is not the first choice, due to a higher sun exposure.

screenshot of HEAL app
A HEAL route in Worms from the main train station to the Rhine promenade: slightly different routes are suggested in the morning and afternoon to avoid heat stress.

The HEAL project: transdisciplinary research to mitigate heat stress

The HEAL project has brought together experts from HeiGIT (Heidelberg Institute for Geoinformation Technology) as well as from the GIScience and the TdLab Geography departments at Heidelberg University. Funded by the Baden-Württemberg Stiftung from 2021 to 2024, the project focused on practical solutions to mitigate heat stress.

The project was initiated with the objective to transcend academic boundaries and address the pressing problem of heat stress in Heidelberg, emphasizing practical applications. In collaboration with the city administration and with the direct involvement of at-risk groups, the initiative enhanced the knowledge base on the effects of heat on vulnerable populations, thus facilitating individual heat adaptation and supporting municipal heat protection and mitigation efforts.

Local citizens were actively engaged through accessible formats such as heat workshops with participatory methods and mobile instant messaging interviews. This approach allowed the identification of challenges and needs that might otherwise have gone unnoticed. This community-based knowledge was then used to develop a locally tailored app to identify routes with lower heat stress. In addition, citizens received information brochures on heat adaptation strategies.

The HEAL project was originally carried out in Heidelberg, where the routing app was launched during the summer of 2024. However, the project has been designed from the beginning to make the approach and the routing application transferable to other cities in Germany, aiming to extend the benefits of this research beyond Heidelberg. Thanks to a close collaboration with the municipality of Worms, the app is now available also for its urban area. We look forward to further expand the app´s availability to other cities.

man holding a presentation
Marco Elischer, Climate Protection Manager for the City of Worms, presenting the HEAL app as part of the Ready4Heat project and Cities Refresh Campaign. Photo: Alicia Göpner / Klima-Bündnis

To learn more about the HEAL project and its impact, go the project webpage: https://heigit.org/heal/. If you have any inquiries in regards to the project, reach out to the project research team with an email to heal@uni-heidelberg.de.