Mercury Rising

Understanding the Impact of Heatwaves on Health

In recent months, many parts of Asia, especially East, Southeast and South Asia, have seen temperatures soar as the phenomenon of extreme heatwaves becomes increasingly common and more intense.

China and Japan logged their hottest August on record this year, while in-person classes in the Philippines were suspended for two days in April due to extreme heat. Soaring temperatures in Thailand during April even saw Bangkok's heat index - which measures what a temperature feels like to the human body, taking into account relative humidity - cross 52°C and was deemed to be "very dangerous." In Singapore, the local meteorological service confirmed that temperatures could surge higher in 2024 than 2023 - the country's fourth-hottest year since records began in 1929.

While warm to hot weather is often expected in these parts of Asia, extreme heat can pose serious risks to human health. We now take a look at the increasingly common occurrences of extreme heatwaves, how they affect the body, and what steps you can take to protect yourself and your loved ones during these increasingly frequent events.

WHAT IS A HEATWAVE?

A heatwave is a prolonged period of excessively hot weather, which may be accompanied by high humidity, particularly in oceanic climate countries. The World Meteorological Organisation (WMO) defines a heatwave as a period of more than five consecutive days where the daily maximum temperature exceeds the average maximum temperature by 5°C or more. However, the definition of a heatwave can vary significantly depending on the climate of the region in question. In Singapore, a heatwave is defined as three consecutive days when daily maximum temperatures are at least 35°C.