emirates7 - The World Health Organisation (WHO) and health and climate experts have cautioned that prolonged heatwaves are no longer just a seasonal discomfort but an escalating health hazard that can be deadly, as record-high temperatures raise concerns over their cumulative impact.

AFP reports that the main risks extend beyond immediate effects like heatstroke and severe dehydration to the worsening of chronic conditions such as cardiovascular and respiratory diseases, which can trigger symptoms or even fatalities days after the heatwave begins. French Health Minister Catherine Vautrin stressed that heat-related health issues may not appear right away, calling for continued vigilance in the days following extreme heat.

While scientific discussions persist about the scale of cumulative effects — with a 2011 Epidemiology study suggesting only a “slight additional effect” after the fourth day, and a 2018 Science of the Total Environment paper minimising the role of duration — newer research highlights emerging dangers. Reports published in 2024 in The Lancet Countdown and Sleep Medicine identified rising temperatures as a “global threat to sleep”, limiting the body’s ability to recover.

These warnings echo the deadly European heatwave of 2003, which claimed over 70,000 lives, emphasising the urgency of understanding this growing threat in the context of accelerating climate change.