April 22, 2024

Climate change is driving an increase in the frequency of extreme heat events that will affect a growing number of people globally. Research has shown that older adults are at a higher risk of dying during a heat wave, but a recent study published in Nature Medicine found that age might not be the most important factor when looking at this population. Physical and cognitive function – such as the ability to perform basic daily tasks – can be a better predictor of an older person’s tolerance for extreme heat.

UHC Faculty member Josiah L. Kephart, PhD, MPH and Assistant Professor of Health Management and Policy at the Drexel Dornsife School of Public Health Safiyyah M. Okoye, PhD, MSN, RN explain the significance of these findings in a commentary published in the same issue. They start by noting that the aging population is of particular concern for urban public health researchers, because “By 2050, the size of the global population over 60 years of age is projected to nearly double, with 80% of older people expected to reside in low- and middle-income countries (LMICs).”

The research they examine studied 13,527 older adults from the nationally representative Chinese Longitudinal Healthy Longevity Survey, and found that older adults with the most severe physical and cognitive impairments had the highest risk of dying during a heat wave. Chronological age was found to not predict the risk of heat-related mortality.

Developing Climate Adaptation Strategies for Older Adults

Understanding what predicts risk is crucial information for creating adaptive strategies for climate change in cities, which are often not developed with older adults in mind, much less older adults with disabilities. Kephart and Okoye note that “Heat adaptation programs such as cooling centers or increasing vegetation for shade will safeguard older adults with functional or cognitive limitations only if such adults have adequate information about the programs and if the programs are easily reached and interacted with, given the physical and cognitive function of the intended beneficiaries.”

“To effectively minimize risks among older adults, new and existing heat adaptation programs should be co-designed with disability advocates to benefit from experiential knowledge. This includes recognition of the importance of care networks that enhance the distribution of information and resources to persons otherwise excluded because of their disability.”

Our Research on the Extreme Heat and Health

The Climate Change and Urban Health in Latin America (SALURBAL-Climate) Project has been working to explore the connections between extreme temperatures and the health of people living in nearly 400 cities across 11 countries in Latin America. Findings from the region to date include:

• On very hot days, a 1-degree centigrade increase in temperature is linked to an almost 6% increase in mortality, and the risk is often greatest for older adults.
• Extreme heat during gestation (and in particular the later months of pregnancy) is associated with lower birth weight.
• Work by the SALURBAL-Climate team suggests that neighborhood greenness may help reduce heat-related health impacts including deaths, especially in arid cities, though understanding how quickly and from what baseline cities are “greening” remains important.
• The team is also documenting connections between greenness and mental health, including the potential for greenness to reduce depressive symptoms.

Thanks to renewed funding from the Wellcome Trust, SALURBAL-Climate will continue to explore these connections and the ways urban adaptation and mitigation policies may help address climate impacts. The recently launched Drexel Climate Change and Urban Health Research Center (CCUH) is also advancing work documenting the impacts of climate change on health and health inequities in diverse cities across Latin America and the United States. The CCUH research team will document the vulnerability of people living in different neighborhoods to extreme heat, and factors (including individual factors like age, gender, race/ethnicity, and socioeconomic status) that contribute to these differences. These findings will support evidence-based climate action in cities across the Americas, including efforts to support and safeguard vulnerable populations.