Por Renan Filho · 2026-10-21
**Lead**
The World Health Organization (WHO) has issued a stark warning that more than one billion children worldwide are at severe risk from intensifying heatwaves, a crisis that Britain cannot afford to ignore. The alert, released in collaboration with UNICEF and the Lancet Countdown, underscores how soaring temperatures are already disrupting lives and economies across the globe. For the United Kingdom, a nation unaccustomed to prolonged extreme heat, the economic toll is mounting rapidly – from agricultural losses and infrastructure damage to rising healthcare costs and diminished labour productivity. The warning comes as UK summer temperatures consistently break records, with the Met Office noting that 2023 was the hottest year on record for the country.
**Context**
The WHO report, published this week, draws on data from 2023 and 2024 to show that children in 80 countries – including the UK – are exposed to heatwaves for an average of at least one extra month per year compared with two decades ago. The agency defines a heatwave as a period of at least three consecutive days where the daily maximum temperature exceeds the 90th percentile of the local historical record. Children are physiologically more vulnerable to heat stress because they absorb heat faster and sweat less efficiently; their developing organs are also more prone to damage. In the UK, an estimated 12 million children live in areas that now experience at least one heatwave per summer, according to the Office for National Statistics. The WHO warns that without swift adaptation measures, heat-related deaths among under-fives in Europe could rise by 20% by 2050.
Beyond health, the economic implications are profound. A 2024 study by the Grantham Research Institute on Climate Change and the Environment estimated that extreme heat cost the UK economy £1.6 billion in lost working hours during the summer of 2023 alone. Sectors such as construction, agriculture, and manufacturing are especially hard hit as outdoor work becomes impossible during peak heat periods. The Confederation of British Industry (CBI) reported that 37% of businesses surveyed in 2025 had already altered their operating hours or invested in cooling technology to cope with recurrent heatwaves. Furthermore, the NHS is under increasing pressure: heat-related hospital admissions for children rose by 15% in 2024 compared with the previous year, according to NHS Digital. The cost of treating heatstroke, dehydration, and respiratory complications is estimated at an additional £240 million annually.
**Analysis**
The WHO warning serves as a critical juncture for the United Kingdom. While the government has published a National Adaptation Programme, critics argue that its focus on flooding and coastal erosion neglects the acute threat of chronic heat. The economic case for investing in heat-resilient infrastructure – from cool roofs and shaded public spaces to expanded green corridors – is becoming undeniable. A report from the London School of Economics estimates that every £1 spent on heat adaptation yields between £4 and £8 in avoided losses over a decade. Yet current public spending on heat resilience in the UK amounts to roughly 0.02% of GDP, far below the levels committed by countries like Spain or Italy.
Moreover, the inequality dimension compounds the economic burden. Low-income households, which often lack access to air conditioning or live in poorly insulated housing, face the highest risk of heat-related health issues, leading to more missed school days and reduced future earning potential. This exacerbates the skills gap and long-term productivity drag. The WHO notes that children from disadvantaged backgrounds are twice as likely to be hospitalised during heatwaves. For the UK economy, which already struggles with low productivity growth, this represents a structural drag that will only intensify as global temperatures climb. Failure to act could trigger a vicious cycle: more heat days reduce child well-being and learning outcomes, which in turn undermines the future workforce’s capacity to drive economic innovation.
**Sources**
- World Health Organization (WHO) and UNICEF report on heatwaves and child health, October 2026. - Lancet Countdown on Health and Climate Change, 2025 policy brief for Europe. - Office for National Statistics (ONS), ‘Heatwave exposure in the United Kingdom’, 2025. - Grantham Research Institute on Climate Change and the Environment, ‘Economic costs of extreme heat in the UK’, 2024. - Confederation of British Industry (CBI), ‘Climate adaptation survey’, 2025. - NHS Digital, ‘Heat-related hospital admissions statistics’, 2024. - London School of Economics, ‘The economics of heat resilience’, 2026.