Heatwaves grow longer and hotter at night, increasing danger

Extended periods of extreme heat and persistently high nighttime temperatures are increasingly straining public health systems worldwide, according to a new analysis released by the World Health Organization. The report, which examined mortality data from more than 150 countries over the past two decades, found that deaths attributable to heat‑related illnesses have risen by several thousand each year, with the most pronounced increases occurring in regions that previously experienced milder climates. Researchers linked the surge to longer‑lasting heat waves, reduced nocturnal cooling, and the growing prevalence of vulnerable populations such as the elderly, outdoor workers, and those with pre‑existing cardiovascular or respiratory conditions.

Health officials attribute the upward trend to a combination of climate‑driven temperature rises and limited adaptive capacity in many communities. While some nations have expanded early‑warning systems and cooling centers, the report warns that without accelerated mitigation and targeted public‑health interventions, the mortality gap could widen further. The findings underscore the urgency of integrating heat‑risk management into urban planning and healthcare strategies to protect at‑risk groups as extreme heat becomes a more permanent feature of the global climate landscape.