The United Kingdom recorded its highest level of child exposure to extreme heatwaves since 1995, with an estimated 10.7 million children, representing 75 per cent of the country's child population affected between January and mid-July 2026, according to new analysis by a child rights organisation, Save the Children.
The findings show that 52 million people, or 74 per cent of the UK population, experienced extreme heatwaves during the first half of the year.
The analysis counted a heatwave only when both daytime and night-time temperatures stayed above the hottest 1 per cent of the past 30 years for at least three consecutive days, recording not merely warm days, but sustained periods when even the nights offered little relief.
The report revealed widespread exposure across the UK. London and the West Midlands recorded the highest levels, with every child in those regions exposed to extreme heatwaves. The South West of England followed with 93 per cent of children affected, while the East Midlands reported 91 per cent, the South East 89 per cent and Wales 84 per cent.
The UK is part of a broader European and global trend. Western Europe has emerged as one of the regions hardest hit, with 57 million children — around two-thirds of the region's child population experienced heatwave in the first half of 2026 compare with 9.4 million in the region's previous worst first half-year.
Globally, the crisis is also intensifying. Save the Children estimates that 132 million children and more than 631 million people worldwide were exposed to extreme heatwaves during the first half of 2026 alone, with numbers expected to rise further as the year progresses.
The organisation noted that heatwaves are unfolding in other parts of the world too and the past three years brought record heat across the Global South. In 2024 alone, South Asia recorded 224 million children exposed to extreme heatwaves, while West and Central Africa reported 128 million and Latin America and the Caribbean 70 million — the highest for those regions since 1990.
The analysis also showed that children's exposure to dangerous heat has increased dramatically over recent decades. During the 1990s and 2000s, an average of 200–230 million children worldwide were exposed to extreme heatwaves each year — around one in 10 worldwide. In the 2020s, that annual average has risen to around 360 million children, or roughly one in seven globally. Two of the four worst years for child heatwave exposure since 1990 have occurred within the past three years.
Save the Children warned that children are more vulnerable than adults to extreme heat because their bodies are still developing and they have a lower capacity to regulate body temperature. Heatwaves increase the risk of dehydration, electrolyte imbalance, fever, respiratory illnesses and kidney disease, while also disrupting children's learning.
The organisation has called for the recognition of children’s unique vulnerabilities to climate change, the delivery of high-quality, affordable funding to lower-income countries, including financing to cut emissions, and the urgent phase out of the use and subsidy of fossil fuels.