Pregnancy, Children, and the Heat Nobody Talks About

For pregnant women, extreme heat poses dangers that extend far beyond discomfort. Pregnancy naturally elevates body temperature by about half a degree Celsius and makes temperature regulation more difficult. When external temperatures soar, pregnant women face increased risks of complications including preterm birth, low birth weight, and miscarriage.

The physiological stress of heat exposure can trigger early labor, reduce fetal growth, and increase stillbirth risk. These dangers are especially acute for women who work outdoors or in environments without adequate cooling, and for those living in areas with limited access to air conditioning.

Dr. Madeleine Thomson, Head of Climate Impacts & Adaptation at Wellcome, notes that these pregnancy complications represent one of extreme heat’s hidden health costs—impacts that rarely make headlines but affect thousands of families during each summer heatwave.

Children face their own distinct vulnerabilities. Their smaller bodies warm up faster than adults, making them particularly susceptible to heat stress. During heatwaves, pediatric emergency rooms see spikes in visits for dehydration, heat exhaustion, and respiratory problems. Children’s higher metabolic rates and less developed thermoregulation systems compound these risks.

The socioeconomic dimension matters enormously. Pregnant women and children in communities with inadequate housing, limited healthcare access, and no air conditioning bear disproportionate burdens. Those who must continue outdoor work during pregnancy or who live in densely built urban areas without green space face heightened exposure.

Sleep disruption affects children particularly severely. When nighttime temperatures remain elevated during “tropical nights” that never drop below 20°C, children struggle to get restorative rest. Sleep deprivation impairs cognitive development, worsens behavioral problems, and compromises immune function.

These impacts on the most vulnerable—those who will live longest with climate change’s consequences—make protecting pregnant women and children from extreme heat a critical public health and justice imperative.