As extreme heat intensifies around the world, the World Health Organization (WHO), the World Meteorological Organization (WMO), UNICEF and the United Nations Population Fund (UNFPA) today launched the first-ever set of priority indicators to help countries track the health impacts of heat on pregnant women, newborns and children. The new framework is designed to strengthen preparedness, improve monitoring, accelerate response. These actions will help protect some of the populations most vulnerable to climate-related health risks.
Studies continue to provide evidence that exposure to extreme heat can harm health from pregnancy to childhood, leading to a 26% increase in the odds of preterm birth. Newborns are also increasingly exposed, with babies under one year of age experiencing 389% more heatwave days in 2024 compared with the 1986 to 2005 baseline period. Globally, an estimated 1.5 billion children are exposed to heatwaves that are becoming more frequent, longer or more severe.
“As our world continues to heat up, it creates new risks for health, and older people, pregnant women, newborns and children are among those least able to escape them,” said Bruce Gordon, Director a.i. of WHO’s Department of Environment, Climate Change, One Health and Migration. “Our health systems need the data to recognize this reality and take action - from protecting people during heatwaves to embedding climate risk consideration into everyday health services.”
The new report recommends that countries monitor preterm births, stillbirths, low birthweight, pregnancy hypertension, child deaths and health-facility visits during extreme heat. Monitoring school attendance can also help reveal how heat is disrupting children’s lives.
“Heat is already affecting our most vulnerable populations, including pregnant women, newborns and children. But what health systems do not count, they cannot respond to,” said Dr Pascale Allotey, Director of WHO’s Department of Sexual, Reproductive, Maternal, Child and Adolescent Health and Ageing. “By tracking outcomes such as preterm birth, child deaths and illnesses, and health-facility visits alongside heat exposure, countries can identify potential impacts and take action to protect women and children.”
Routine health data and heat-exposure data such as air temperature can help identify possible heat-related signals that can assist countries in identifying unusual changes during periods of extreme, conduct further investigation and act accordingly.
The information can help health authorities prepare facilities for increased demand, strengthen warnings to pregnant women and families, identify communities at greatest risk and improve heat-health planning.
As extreme heat is fast becoming a common feature of a warming world, WHO is calling on countries to strengthen their ability to monitor and respond to its health impacts. By using the new priority indicators in this report, governments can better identify risks, target interventions and protect pregnant women, newborns and children from preventable harm.
WHO also urges all countries to develop and implement heat-health action plans that are context-specific, and that integrate the needs of these vulnerable populations, strengthen early warning systems and trigger timely action when heat risks emerge.
About WHO
Dedicated to the well-being of all people and guided by science, WHO leads and champions global efforts to give everyone, everywhere, an equal chance at a safe and healthy life. We are the United Nations’ agency for health that connects nations, partners and people in more than 150 locations – leading the world’s response to health emergencies, preventing disease, addressing the root causes of health issues and expanding access to medicines and health care. Our mission is to support all countries to promote, provide and protect health. “Together for health. Stand with science”, the theme of World Health Day 2026, marks a year-long campaign to highlight science as the foundation for protecting health and well-being worldwide.