Feeling the Heat: Climate Change, Extreme Heat Events, and Communities at Risk

Extreme heat, or temperatures higher than 90 degrees Fahrenheit or 32 degrees Celsius for at least two days, accounts for the highest number of weather-related deaths annually in the U.S. Climate change is causing these heat events to be more frequent, longer lasting, and severe. In 2021, people experienced 3.7 billion more heatwave days globally than the annual average from 1986 to 2005. Heat-related deaths rose 68 percent from the 2000–2004 and 2017–2021 periods.

Extreme heat can lead to heat exhaustion and heat stroke. Additionally, extreme heat and other extreme weather events caused by climate change are linked to hunger among nearly 100 million people worldwide. Young children, older adults, people with chronic disease, and economically marginalized groups are the most at risk, but anyone can suffer the effects. Having more of these extreme heat events in the near future will increase heat-related illness and death due to complications.

How does extreme heat relate to health and equity?

Urban populations are at greater risk of being affected by extreme heat events. The urban heat island effect causes higher temperatures in areas with low vegetation, sun-absorbing surfaces such as paved roads, and reduced windflow due to narrow streets and tall buildings. Temperatures in urban areas can be 1.8–5.4°F warmer than their surroundings during the day, and at night that difference can be as much as 22°F due to heat being retained by the built environment.

Urban heat most strongly affects those with long exposure to heat such as people experiencing homelessness; who are sensitive to heat, like children and the elderly; and who struggle to respond and prepare for these extreme weather events, including those who are unable to afford air conditioning or electricity.

How is JSI involved in this area?

Community resiliency is crucial for the health and well-being of people who are under-resourced during these weather events. As a leader in public health, JSI is uniquely positioned to work directly with health departments, neighborhood groups, and local leaders to strengthen climate resilience plans that are developed by and for the community. JSI understands that by focusing on community engagement and expertise, building trust, and training community health workers in emergency preparedness and response, communities are better prepared to support individuals through extreme heat events caused by climate change.

JSI is working on the Asia Resilient Cities Project, which is mitigating development challenges in secondary cities in Asia by promoting sustainable growth; supporting resilient, low-carbon infrastructure; and integrating climate change and environmental considerations into development approaches. JSI is collaborating with residents to set the city agenda, change the economy, and advocate for what their communities need. Partner cities will move along the three steps of the USAID Resilience Conceptual Framework to overcome challenges and sustain results, ultimately creating more resilient and livable environments.

From 2016 to 2020, JSI facilitated strategic planning in Cambridge, Massachusetts for climate change resilience. JSI reviewed evidence-based practices tied to extreme heat and conducted a gap analysis among agencies, health providers, and residents to identify several important strategies for the city to focus on. These strategies incorporated multiple facets of the community, including health providers and emergency responders providing education to patients and triage at public sites; community groups setting up cooling shelters, misting stations, and access to A/C units; and community health workers working with isolated seniors. Youth in Cambridge also participated in a video project to educate community members about extreme heat and flooding projections.

This project, and others like them, demonstrate the history of JSI’s commitment to environmental health. JSI established a Center for Environment and Health in 1989 with a focus on community technical assistance. The center was formed to assist community-based organizations, largely nongovernmental, to promote local environmental health. In 1991, JSI wrote the guidance “Environment and Health: Learn about the Environment Where You Live Protect the Health of Your Family and Community.”

JSI continues to expand its environmental portfolio, and supports the Climate and Environment Initiative with its sister organizations World Education, Inc. and the Partnership for Supply Chain Management. Learn more in the JSI Environmental Health overview.