Excessive heat harms young children’s development, study suggests
Climate change-including high temperatures and heat waves-has been shown to pose serious risks to the environment, food systems, and human health, but new research finds that it may also lead to delays in early childhood development.
Published in the Journal of Child Psychology and Psychiatry, the study found that children exposed to higher-than-usual temperatures-specifically, average maximum temperatures above 86 °F (30 °C)-were less likely to meet developmental milestones for literacy and numeracy, relative to children living in areas with lower temperatures.
“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,” says lead author Jorge Cuartas, assistant professor of applied psychology at NYU Steinhardt. “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.”
Cuartas and his co-authors analyzed data for 19,607 three- and four-year-olds from Gambia, Georgia, Madagascar, Malawi, Palestine, and Sierra Leone, selected because they had detailed data on child development, household factors, and climate, which allowed the researchers to estimate children’s exposure to different temperatures.
To assess children’s development, the researchers used the Early Childhood Development Index (ECDI), which measures basic developmental milestones in four areas: skills related to reading and numbers (literacy and numeracy), social-emotional development, approaches to learning, and physical development. They also used 2017-2020 data from the Multiple Indicator Cluster Surveys (MICS), a database with demographic information and indicators on wellbeing, including education, health, nutrition, and sanitation. Merging the ECDI and MICS data with climate data on average monthly temperatures, they determined whether there were any links between heat exposure and early childhood development.
They found that children who were exposed to average maximum temperatures above 86 °F (30 °C) were 5 to 6.7 percent less likely to meet basic developmental milestones for literacy and numeracy compared to children exposed to temperatures lower than 78.8 °F in the same region and season. These effects were more pronounced among children from economically disadvantaged households, households with less access to clean water, and from urban areas.
“We urgently need more research to identify the mechanisms that explain these effects and the factors that either protect children or heighten their vulnerability. Such work will help pinpoint concrete targets for policies and interventions that strengthen preparedness, adaptation, and resilience as climate change intensifies,” says Cuartas.
Reference:
Cuartas, J., et al. (2025). Ambient heat and early childhood development: a cross‐national analysis. Journal of Child Psychology and Psychiatry. doi: 10.1111/jcpp.70081. https://acamh.onlinelibrary.wiley.com/doi/10.1111/jcpp.70081
