New data suggest climate-related heat exposure may influence early developmental trajectories, particularly among vulnerable children.
Exposure to excessive heat early in life may be associated with delays in foundational developmental skills, according to new research from New York University examining children across 6 countries with diverse climates and socioeconomic contexts. The study, published in The Journal of Child Psychology and Psychiatry, suggests that rising global temperatures could have implications not only for physical health but also for early cognitive development.1
Researchers analyzed early childhood development outcomes among children aged three and four years living in Georgia, The Gambia, Madagascar, Malawi, Sierra Leone, and the State of Palestine. Using geographic and time-stamped data, the study assessed whether ambient heat exposure from birth through early childhood was associated with differences in developmental milestones, focusing on literacy and numeracy skills in particular.
The primary outcome measure was the Early Childhood Development Index (ECDI), a standardized indicator used to assess whether children are developmentally on track across multiple domains. Investigators merged ECDI data with temperature data from the ERA5-Land Monthly Aggregated Climate Dataset, calculating the mean monthly maximum temperature each child experienced from birth to the time of assessment. The final sample included 19,607 children surveyed between 2017 and 2020 through Multiple Indicators Cluster Surveys.
"We used linear probability models with geographic and seasonality fixed effects to account for baseline climatic conditions, as well as other individual and contextual covariates to address potential selection bias,” wrote the investigators.
Results showed that children exposed to average maximum temperatures above 32°C were less likely to be developmentally on track compared with children exposed to cooler conditions. These associations persisted even after adjusting for baseline climatic conditions and other contextual factors.
Domain-specific analyses indicated that the negative effects of heat exposure were most pronounced in literacy and numeracy skills. According to the study, children exposed to average maximum temperatures above 30°C were 5% to 6.7% less likely to meet basic developmental milestones in these domains compared with peers exposed to temperatures below 26°C in the same region and season.2
“While heat exposure has been linked to negative physical and mental health outcomes across the life course, this study provides a new insight that excessive heat negatively impacts young children’s development across diverse countries,” said Jorge Cuartas, assistant professor of applied psychology at NYU Steinhardt and lead author of the study. “Because early development lays the foundation for lifelong learning, physical and mental health, and overall well-being, these findings should alert researchers, policymakers, and practitioners to the urgent need to protect children’s development in a warming world.”
Subgroup analyses revealed that the adverse associations between heat exposure and development were not evenly distributed. The negative impacts were particularly severe among children living in economically disadvantaged households, those residing in urban areas, and children lacking access to adequate water and sanitation.1,2
The authors concluded that their findings highlight the need for targeted policies and interventions aimed at mitigating the developmental risks associated with climate change.1
“We urgently need more research to identify the mechanisms that explain these effects and the factors that either protect children or heighten their vulnerability,” Cuartas said. “Such work will help pinpoint concrete targets for policies and interventions that strengthen preparedness, adaptation, and resilience as climate change intensifies.”2
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