Three Essential Lessons for Cities Facing Extreme Heat

Last month, the Community Data Health Initiative (CDHI) hosted the Urban Heat Resiliency Design Workshop, a full-day event bringing together experts and representatives of eight U.S. cities to discuss heat mitigation strategies. Participants engaged in a series of panels and discussions on heat’s impact on health, best practices to address acute and chronic heat, and strategies to solicit funding and buy-in for this work. Here we highlight three learnings that our participants found particularly insightful.

1. Pregnant people, infants, and young children are especially sensitive to extreme heat, highlighting the importance of early interventions.

Dr. Lindsey Burghardt, the Chief Science Officer at the Center on the Developing Child at Harvard University, discussed the impacts of heat on developing biological systems— highlighting that these systems are most sensitive during pregnancy, infancy, and early childhood. Evidence shows that periods of high temperatures are associated with increased rates of stillbirth, premature birth, and lower birth weights, which are then linked to higher risk of developing health complications later in life. For young children, their bodies heat up more quickly, they have less ability to sweat to regulate body temperatures, and they often rely on adults to access water and cooling. This sparked a conversation on how to focus interventions around these populations and time them to maximize preventive benefits over lifetimes. Ideas included targeted public awareness campaigns, partnerships with frontline healthcare workers to communicate risks to pregnant patients, and efforts to reduce heat exposure where kids learn and play. Miami-Dade County shared an example of a public awareness campaign where they communicated the heightened risks and resources available to pregnant people via infographics, billboards, and video essays from prominent figures like Jane Fonda.

2. Heat disrupts sleep, learning, and mental and behavioral health, which can have compounding and lifelong impacts on overall well-being. This is a powerful lens to communicate urgency and motivate action. 

It is widely known that extreme heat causes acute health complications, like heat-related illnesses. However, heat also impacts numerous other aspects of health and well-being that can compound over a lifetime. Higher temperatures disrupt sleep which can lead to challenges, particularly in early childhood, including reduced language development and problem-solving skills. Heat also disrupts learning in the classroom: research shows that every 1-degree-Fahrenheit increase in average outdoor temperature over a school year reduces student learning by 1 percent, impacting standardized test scores and student success. Participants discussed how highlighting these long-term impacts, particularly for mothers and young children, can help build buy-in from residents and policymakers alike by demonstrating the consequences of inaction and conveying the hope for interventions to have a multiplier effect. For example, Los Angeles is working to promote student wellbeing through transforming school-yards filled with asphalt into green spaces, working to reduce temperatures and reduce the impacts of extreme heat on learning outcomes. 

3. Incorporating built environment solutions can enhance urban shading and address socioeconomic disparities in heat risk. Cities should diversify their approach beyond planting trees.

Shade is known to be one of the most effective cooling methods and can be created by any vertical object, yet it is often addressed solely through tree-planting initiatives. Dr. Kelly Turner, the associate director of the Luskin Center for Innovation at the University of California, Los Angeles, spoke about the concept of shade deserts and shade equity and encouraged cities to consider other means of creating shade through the built environment, like bus shelters and playground structures. This diverse approach is important given that some cities actually get more shade from buildings than trees, like Los Angeles, Philadelphia, and Boston. The group further discussed how shade deserts—areas lacking sufficient shade for safe outdoor activity—demonstrate the varying experiences of hot days and highlight the impact of socioeconomic disparities on heat risk. This is crucial when considering access to resources, such as air conditioning and green spaces, and exposure, such as whether one works outdoors.

To learn more about the heat resiliency efforts of cities, read our articles Mapping a Path to Resilience in Los Angeles, The Role of Chief Heat Officers: Jane Gilbert, and Building Extreme Heat Resilience: Tucson Million Trees. To learn more about CDHI, please see our project page.