RISING global temperatures are fuelling more frequent and intense heatwaves that pose a growing threat to human health, says a Malaysian public health expert who warns that standard temperature readings may not reflect the true risks of extreme heat.
In an interview with China’s Xinhua news agency, Dr Victor Hoe Chee Wai of the Department of Social and Preventive Medicine, Faculty of Medicine, Universiti Malaya, called for updated criteria and metrics to better assess the health impacts of heatwaves, particularly in tropical regions.
“When heatwaves strike, it’s important not to rely solely on the temperature shown on a standard thermometer,” he said. “Greater attention should be given to the ‘wet-bulb globe temperature’, which considers factors such as ambient temperature, humidity, wind speed and radiant heat.”
According to Dr Hoe, this metric offers a more accurate measure of heat stress on the human body—particularly for those working outdoors or in non-air-conditioned environments.
He explained that a wet-bulb thermometer is created by wrapping a standard thermometer in a damp cloth and placing it in moving air.
The evaporative cooling effect lowers the temperature reading, producing a result that more closely represents actual heat stress.
Unlike the standard air temperature (also known as the dry-bulb temperature), the wet-bulb globe temperature more accurately reflects the environmental conditions affecting human health.
“This is especially relevant for Malaysia,” Bernama - Xinhua cited Dr Hoe saying, “a tropical country situated near the equator, where high temperatures and humidity persist year-round, with average annual temperatures ranging from 21 to 32 degrees Celsius.”
He also warned that dangerous heat conditions are no longer confined to tropical regions, as global temperatures and humidity levels continue to rise. Cooler regions, previously considered safe, are now increasingly vulnerable to the health impacts of extreme heat.
Dr Hoe’s comments come amid growing international concern over climate-related health risks, as countries across the globe experience record-breaking temperatures and prolonged heat events. - July 20, 2025
