Malaysia at risk of deadly humidity threat

The Star

08-06-2025

PETALING JAYA: It's not merely the heat – it's the humidity that poses a lethal threat.
Experts warn of a wet-bulb temperature (WBT) threat as Malaysia sweats through a silent, rising danger. And with the heat expec­ted to rise in the coming months, Malaysians should be prepared to deal with this lesser-known but deadly phenomenon.
A patient's core body temperature will normally rise to dangerous or even fatal levels in a matter of hours, according to the experts.
Prof Dr Sharifa Ezat Wan Puteh of Universiti Kebangsaan Malay­sia (UKM) said studies have shown that WBT can occur even when the temperature is as low as 31°C.
'The US National Weather Ser­vice considers WBT temperatures of 31°C or higher to be in 'extreme danger'. This is considered relatively low, and it supports the idea that the human body's ability to cope with heat stress is compromised even at lower thresholds than once believed,' she said when contacted yesterday.
Sharifa said that certain groups are more susceptible to the dangers of WBT, such as the elderly, pregnant women, children, outdoor workers and individuals with underlying health comorbidities.
'Staying in shaded areas, hydra­ting frequently, limiting physical exertion and outdoor exposure, and wearing light, breathable clothing may reduce the risk of hyperthermia (internal body temperature rising),' she added.
Sharifa suggested that the res­pec­­tive agencies work together to alert the public to the dangers of extreme heat exposure and WBT.
'The Department of Occu­patio­nal Safety and Health (DOSH) should also advise officers to keep workers out of open areas that are exposed to heat, wind or humidity,' she added.
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Sustained temperatures bet­ween 31°C and about 35°C, along with humidity levels above 90%, are known to cause WBT in a specific area. It is considered extreme hyperthermia and often fatal if the core body temperature reaches 42°C and above.
On June 2, the Meteorological Department (MetMalaysia) issued a Level 1 advisory after six areas in Peninsular Malaysia experien­ced maximum daily temperatures of between 35°C and 37°C for three consecutive days.
Universiti Malaya (UM) public health medicine specialist Prof Dr Victor Hoe voiced concern over the prolonged heat and humidity the nation is currently facing, which is expected to last through the coming months.
'What we're facing is more than just uncomfortable weather.
'This is a growing public health and safety concern that requires attention, empathy and coordinated action,' he said when contacted.
Hoe said that a person's body will naturally regulate internal temperature by producing sweat, which cools the body when it evaporates.
'But when the air is very humid, sweat doesn't evaporate efficiently. This reduces our body's ability to cool down, leading to overheating, which can be dangerous or even deadly,' he said.
Signs to watch for heat exhaustion or heatstroke include tiredness, dizziness, nausea, confusion, rapid pulses and unconsciousness.
Hoe urged the public to remain adequately hydrated by drinking water consistently throughout the day.
'Avoid outdoor activity during the hottest part of the day, such as between 12pm and 3pm.
'Wear loose, light-coloured clo­th­ing and stay in shaded or air-con­ditioned areas.
'Check in with elderly neighbours or family members, especially those living alone,' he said.
UM's vice-chancellor (research & innovation) Prof Dr Sanjay Rampal described WBT as a public health threat which may happen even if temperatures are lower than 35°C.
'Currently, MetMalaysia's three-tier alert system focuses only on dry-bulb temperature but does not account for the role of humidity. We may consider a heat index that combines temperature and humidity measurements,' he suggested.
Dr Sanjay added that MetMalay­sia should work in collaboration with relevant agencies by provi­ding them with meteorological data, which could then be translated into specific health advisories for the general public.
In response to the rising tempe­ratures, Dr Sanjay cautioned parents against leaving their children or elderly relatives unattended in parked vehicles.