WHO warns of rising heat risks as 1.5 billion children face growing exposure

The World Health Organization (WHO) and three United Nations agencies have introduced a global framework to help countries detect, monitor and respond to the growing health dangers that extreme heat poses to pregnant women, newborns and children.

Launched on October 21, 2026, the framework sets out key health indicators that governments can use to track heat-related complications, improve emergency planning and strengthen protection for vulnerable groups as heatwaves become more frequent, longer and more severe across the world.

The initiative was developed jointly by WHO, the World Meteorological Organization (WMO), the United Nations Children's Fund (UNICEF) and the United Nations Population Fund (UNFPA).

The agencies warn that high temperatures can have serious consequences for women during pregnancy, increasing the risk of premature delivery, stillbirth, low birth weight and other health complications.

Data presented in the framework links exposure to extreme heat with a 26% increase in the odds of preterm birth, raising concerns about the effects of rising temperatures on the health of mothers and their babies.

The report also points to a sharp increase in the number of heatwave days experienced by infants. Babies under one year old recorded 389% more heatwave days in 2024 compared with the baseline period of 1986 to 2005.

At the same time, an estimated 1.5 billion children worldwide are exposed to heatwaves that are becoming more frequent, lasting longer or reaching greater levels of severity.

Bruce Gordon, the acting director of WHO's Department of Environment, Climate Change, One Health and Migration, said health systems need reliable data to understand the growing threat and take appropriate action.

“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,” he explained.

“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 framework calls on countries to monitor a range of health outcomes during periods of extreme heat. These include premature births, stillbirths, low birth weight, high blood pressure during pregnancy, child deaths and visits to health facilities.

It also recommends tracking school attendance to help authorities understand how extreme temperatures affect children's education and daily activities.

By monitoring these indicators, countries could identify changes in health outcomes during heatwaves and determine whether the effects of high temperatures are placing additional pressure on families and health services.

WHO's director of Sexual, Reproductive, Maternal, Child and Adolescent Health and Ageing, Dr Pascale Allotey, said collecting information on health outcomes alongside exposure to extreme heat would help governments recognise risks and respond more effectively.

“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,” she said.

“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.”

Under the framework, governments are encouraged to bring together information from routine health records and data on heat exposure, including air temperatures.

Combining the two sources of information could help health officials spot unusual changes in illness, birth outcomes and deaths during periods of extreme weather. Authorities would then be better placed to investigate possible links to heat exposure and decide whether further action is necessary.

The information could also help hospitals and other health facilities prepare for a rise in patients during heatwaves. Health authorities could use the findings to improve warnings for pregnant women and families, identify communities at greater risk and strengthen plans for dealing with heat-related health emergencies.

WHO is urging governments to develop and put in place heat-health action plans that reflect local conditions and address the specific needs of pregnant women, newborns and children.

The agency is also calling for stronger early-warning systems and clear procedures to ensure timely action whenever extreme heat threatens public health.

The framework comes amid growing concern over the health effects of rising global temperatures, particularly among people who may have limited ability to avoid prolonged exposure to extreme heat.

Pregnant women, newborns and children are among the groups that health authorities want to protect through better monitoring, early warnings and improved preparedness.

The recommended indicators are intended to help countries identify emerging threats, direct resources towards communities facing the greatest risks and take steps to prevent avoidable health complications.

The four agencies say stronger monitoring, supported by effective preparation and timely responses, will be important in helping health systems deal with the growing health burden linked to extreme heat and protect the health of mothers and children.