Large-scale study links children’s extreme heat exposure to reduced performance across numerous cognitive domainsThe increasing frequency and intensity of extreme heat events are serious consequences of climate change, with children among those particularly vulnerable to harmful effects. Extreme heat poses significant public health concerns, as high temperatures and heat stress have been associated with increased mortality and illness, adverse pregnancy outcomes, and poorer mental health. These risks may be greater for children from socioeconomically disadvantaged families, who may have less access to resources that can reduce heat exposure. Although previous research has linked extreme heat exposure to a range of health risks, less attention has been given to its potential effects on children’s cognitive function. This study aimed to address this gap by examining the relationship between extreme heat exposure and cognitive function. Using data from the large-scale Adolescent Brain Cognitive Development (ABCD) study, this research examined whether greater exposure to extreme heat was associated with differences in children’s cognitive performance across multiple domains. The study also considered factors that may influence cognitive outcomes, including family and neighborhood socioeconomic status and race/ethnicity. By examining these relationships, the study aimed to clarify how climate change may impact youth development.
The study analyzed baseline data from the ABCD study, a large-scale research program in the US that is examining the developmental trajectories of preadolescent children. The data was collected from a nationally representative cohort that was racially, ethnically, and socioeconomically diverse. The analysis included data from 11,878 children (age 9-10). Cognitive performance was assessed using standardized measures from the National Institutes of Health (NIH) Toolbox, including total composite (overall cognitive performance), fluid composite (cognitive reasoning and adaptability), and crystallized intelligence (accumulated knowledge and skills), as well as reading ability, picture vocabulary, pattern recognition, card sorting, and list recall tasks. These measures evaluated memory, learning, and general cognitive ability. Parent-reported data included heatwave exposure, race/ethnicity, age, gender, parental education, and family socioeconomic status (SES). Economic indicators for participants' neighborhoods were also collected as a measure of area-level SES. Statistical analysis examined the relationship between heatwave exposure and cognitive outcomes while accounting for differences in age, gender, race/ethnicity, and SES.
Significant relationships were found between heatwave exposure and cognitive performance. Children with higher levels of heatwave exposure had lower scores across all assessed cognitive domains, including total composite cognitive ability, fluid and crystallized intelligence, reading, picture vocabulary, pattern recognition, card sorting, and list recall. The strongest relationships were found for learning outcomes, particularly pattern recognition and reading ability, and for general cognitive ability, including total composite, fluid composite, and crystallized intelligence. The relationships between heatwave exposure and memory outcomes, including list recall and card sorting, as well as picture vocabulary, were somewhat weaker but remained statistically significant. These relationships remained significant even after accounting for demographic factors, race/ethnicity, family SES, and neighborhood SES.
Results suggest that extreme heat exposure is linked to reduced learning, overall cognitive ability, and memory in children. These findings align with a related study (conducted by the same researchers) that found an association between extreme heat and diminished cognitive function. This related study further reported that Black children, those living in lower SES households, and those residing in economically disadvantaged neighborhoods face higher exposure to extreme heat. Therefore, children who are disadvantaged by systemic inequities are likely also disproportionately affected by climate change stressors, which may further exacerbate developmental disparities. The findings support targeted interventions to reduce vulnerable populations' disproportionate exposure to extreme heat, including urban greening initiatives that help mitigate the cognitive impacts of heat exposure. The authors conclude that “as climate change intensifies, proactive measures to mitigate the cognitive and developmental impacts of extreme heat are essential for promoting equity and safeguarding the well-being of all children.”
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