The World Health Organisation (WHO) has identified extreme heat as a growing health risk for pregnant women, newborns and children, with rising global temperatures linked to premature births and increased childhood illnesses.

The WHO, World Meteorological Organisation (WMO), United Nations Children’s Fund (UNICEF) and United Nations Population Fund (UNFPA) have introduced the first set of priority indicators to help countries monitor the health effects of heat exposure on these vulnerable groups as extreme temperatures intensify worldwide.

According to WHO, studies have shown that exposure to extreme heat increases the odds of preterm birth by 26 per cent, while an estimated 1.5 billion children globally are exposed to heatwaves that are becoming more frequent, longer or more severe.

The report also revealed that babies under one year of age experienced 389 per cent more heatwave days in 2024 compared with the baseline period of 1986 to 2005, highlighting the growing exposure of newborns to potentially harmful environmental conditions.

Speaking on the development, the Acting Director of WHO’s Department of Environment, Climate Change, One Health and Migration, Bruce Gordon, said extreme heat was creating new health risks, particularly for populations with limited ability to protect themselves from rising temperatures.

“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 said.
Gordon said health systems needed reliable data to recognise the scale of the threat and respond effectively, including protecting people during heatwaves and incorporating climate risks into routine health services.

To help countries identify and respond to these risks, the new framework recommends monitoring a range of health outcomes, including preterm births, stillbirths, low birthweight, hypertension during pregnancy, child deaths and visits to health facilities during periods of extreme heat.

It also recommends monitoring school attendance, which can provide insight into how rising temperatures disrupt children’s education and daily activities.

The Director of WHO’s Department of Sexual, Reproductive, Maternal, Child and Adolescent Health and Ageing, Dr Pascale Allotey, said health systems needed to systematically track the effects of extreme heat to identify emerging threats and protect vulnerable populations.

“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.

Allotey explained that tracking outcomes such as preterm births, child deaths, illnesses and health facility visits alongside heat exposure would help countries identify potential health impacts and take appropriate action.

According to the report, countries can combine routine health records with heat-exposure data, including air temperature measurements, to identify unusual changes in health outcomes during periods of extreme heat.

Such information could help health authorities anticipate increased demand for medical services, strengthen heat warnings for pregnant women and families, identify communities facing the greatest risks and improve national heat-health planning.

The UN agencies said the indicators were intended to help governments move beyond measuring temperatures to assessing how extreme heat affects people’s health, particularly those most vulnerable to climate-related risks.

They stressed that countries needed to strengthen their capacity to monitor and respond to the health consequences of extreme heat, using the indicators to identify risks, target interventions and prevent avoidable harm.

WHO also called on all countries to develop and implement context-specific heat-health action plans that address the needs of pregnant women, newborns and children.

The organisation urged governments to strengthen early warning systems and ensure that warnings trigger timely action to protect vulnerable populations as extreme heat becomes an increasingly common feature of a warming world.