The human body versus scorching heat: Which will win the race?

If there is one impact from man-made climate change that is pushing the human body to its limits, it is heat.

- David Fogarty

It is a killer. And extreme heat is a risk to everyone, no matter where they live. The World Health Organisation (WHO) says heat stress is the leading cause of weather-related deaths, and the number of people exposed to extreme heat across the globe is growing exponentially.

Asia is especially vulnerable because it has about 60 per cent of the world's population and rapidly growing megacities that trap heat, exacerbating the impact of heatwaves.

Those most vulnerable include millions of outdoor workers in construction, ports and farming, and food delivery riders. Children are also at risk, since many in the region attend schools that have no air-conditioning.

And children's bodies heat up faster. The scorchingly hot weather in 2024 brought life to a standstill across Asia, disrupting work, closing schools, overwhelming hospitals and damaging crops.

Across the globe, people and places are struggling to adapt fast enough as the mercury keeps climbing, with 2023 the hottest year on record and 2024 shaping up to be even warmer.

"We often underestimate the risks and impact of rising temperature due to its gradual increases, but extreme heat events are becoming more frequent and prolonged," said Associate Professor Jason Lee, director of the Heat Resilience and Performance Centre at NUS Medicine.