Performance Under Fire: Older Adult Cognitive Risks and Protections Under Heat Strain.

BACKGROUND AND OBJECTIVES

Although extreme heat events disproportionately affect older adults and the importance of cognition is known, research examining older adult cognition under heat stress is limited. This study examines the relationship between risk/protective factors and heat strain on older adult cognition, employing a social-ecological model.

RESEARCH DESIGN AND METHODS

Retrieved from the 1996-2016 waves of the Health and Retirement Study, our study used older adults aged 50 and older and their spouses residing in the United States. Individual-fixed effects models estimated changes in cognition as measured by fluid and crystallized intelligence scores in response to extreme heat days. This study further estimated interactions of extreme heat with protective/risk factors for cognition (i.e., education, physical activity, social engagement, and genetic risk for Alzheimer's disease).

RESULTS

Our results demonstrated that extreme heat days were associated with fluid but not crystallized intelligence scores. Educational attainment, mild physical activity, and social contacts with children moderated this relationship. Furthermore, Alzheimer's disease polygenic scores moderated the correlation between extreme heat days and crystallized intelligence scores.

DISCUSSION AND IMPLICATIONS

An increasing frequency of extreme heat events and an aging population globally highlight the need for policies and interventions building resiliency in older adults. Actions promoting the protective modifiable behaviors to older adult cognition identified by our study can lead to healthier individuals and communities.