Climate change is already adding a month or more of dangerous heat to the lives of hundreds of millions of young children, according to new research from the Vrije Universiteit Brussel. The study, published in Science Advances, estimates that up to 560 million children aged 0–9 are now exposed to at least one additional month of heat stress every year compared with a world without human-induced warming.
Children are not just smaller adults. Their bodies are still developing, and they have a harder time regulating temperature. They sweat less per kilogram of body weight and have a higher metabolic rate, which means they heat up faster during extreme heat. This makes them particularly vulnerable to heatstroke, kidney failure, and lung damage, as well as indirect effects such as food and water insecurity.
“Climate change is already causing hundreds of millions of children to suffer from dangerous heat worldwide, posing severe risks to their health,” said Rosa Pietroiusti, the study’s lead author. “At the same time, poverty, inadequate housing, limited access to cooling, and overstretched healthcare systems leave many children with few ways to protect themselves from the heat.”
Unequal burden across the globe
The researchers found that children’s exposure to heat stress outpaces every other age group. For comparison, about 190 million people aged 60–69 face an additional month of heat stress—less than a third of the number of children affected. The largest increases in humid heat are occurring in tropical regions and poorer countries, particularly South Asia, Southeast Asia, and West Africa, where many of the world’s youngest populations live.
In these regions, children are often doubly exposed. They face direct physiological strain from the heat, but also indirect threats like the spread of mosquito-borne diseases, disrupted feeding practices, and complications at birth. The authors note that children in the worst-affected areas are likely to be more socioeconomically vulnerable, with limited access to cooling or adequate healthcare.
The findings echo concerns raised by other European institutions. For instance, UNICEF has warned about malnutrition crises that are exacerbated by climate shocks, and glacial collapses in the Himalayas have highlighted the broader risks of a warming planet. While these events occur far from Europe, they have implications for European development aid and migration patterns.
A worrying outlook for the coming decades
Even under optimistic warming scenarios, the picture does not improve. If the world warms by 1.5°C, the researchers project that 620 million children aged 0–9 would experience at least one additional month of heat stress per year, and 390 million would face at least five months of heat stress annually. At 2.0°C of warming, that number rises to 650 million children.
These projections assume that population and age structures remain similar to today. But even as global populations age, children will remain disproportionately exposed. “Children are particularly vulnerable to climate change impacts and will face intensifying effects of climate change during their lifetimes,” the authors wrote.
The study adds to a growing body of evidence that climate change is not a distant threat but a present-day crisis for the youngest generation. For European policymakers, the findings reinforce the need for ambitious emissions cuts and for adaptation measures that protect the most vulnerable, both at home and abroad. As France’s presidential candidates grapple with climate credibility, the data from Brussels offers a stark reminder of what is at stake.
While the study focuses on global numbers, its authors stress that the solution lies in rapid, equitable action. “The good news is that we know what needs to be done,” said Pietroiusti. “Reducing emissions quickly and investing in resilient health systems and social protection can make a real difference for millions of children.”
