Researchers affiliated with the Barcelona Institute for Global Health and partner institutions explored how extreme temperatures in early life shape a child’s brain development. The findings were reported in Nature Climate Change.
Past studies have linked temperature swings to several child health concerns, including heightened anxiety, mood disorders, and aggressive behavior, yet the exact brain structure changes driving these effects remain to be clearly understood.
The investigators analyzed data from 9,896 pregnant women and 2,681 children aged 9 to 12. They observed that exposure to both cold and heat during early life correlated with notable alterations in the microstructure of white matter, which can influence neural connectivity and cognitive performance.
Specifically, cold exposure from the third month of pregnancy through 15 months of life and heat exposure from nine months of life through 2 years and 6 months were linked to higher global white matter diffusivity values. Elevated diffusivity is interpreted as weaker microstructural integrity of white matter.
In a more granular analysis, the researchers mapped precise windows of heightened sensitivity to extreme temperatures. Cold sensitivity tended to span from the prenatal period through early childhood. Heat sensitivity appeared from birth to around age three across several white matter tracts, including the cingulate fasciculus, corticospinal tract, and superior longitudinal fasciculus.
The study highlighted that children in low socioeconomic settings represent the most vulnerable population to extreme temperature effects, underscoring a potential interaction between environmental exposure and social determinants of health.
Overall, the work adds to a growing body of evidence that environmental temperature exposure can influence brain development, with implications for long-term cognitive and behavioral outcomes.