WE talk about heat in Malaysia the way we talk about the weather: as something to put up with, not something to plan for. But the numbers tell a different story.
The Malaysian Meteorological Department (MetMalaysia) expects the current El Niño weather cycle to peak between March and May 2027, with temperatures likely to pass the record of 40.1°C. In early May this year, the Health Ministry had already logged 56 heat-related illnesses nationwide, including two deaths from heat stroke.
I think often about what heat does to the body before it shows up as an illness. Having spent much of my career in maternal and reproductive health, one gap stands out to me: heat is a pregnancy risk, but almost no one is talking about it that way.
A major 2024 review in Nature Medicine, based on nearly 200 studies across 66 countries, found that with every extra degree of heat, the risk of premature birth rises by 4%. During heatwaves specifically, that risk jumps to 26%. High heat is also linked to a 29% higher risk of low birth weight, and it is now strongly linked to dangerously high blood pressure and diabetes during pregnancy.
None of this shows up in Malaysia’s heat guidance, because Malaysia does not actually have a heat guidance. We are one of the few Asean countries without a national climate adaptation plan.
The only rule we have on heat, issued by the Occupational Safety and Health Department in 2016, is voluntary. As one human rights defender put it recently, there is no real incentive for employers to act, so almost nothing happens at the worksite. Even newer city planning documents tend to treat heat as an afterthought next to floods and landslides.
We are, in short, improvising our way through a hazard we already know how to plan for.
Ahmedabad, India, shows what planning can do. After a 2010 heatwave killed over 1,300 people in a single month, the city built South Asia’s first Heat Action Plan: a colour-coded early warning system tied to forecasts, coordination between health, disaster management, and emergency services, outreach to the most vulnerable, and training for healthcare workers to spot heat illnesses early. This simple, low-cost plan is estimated to save around 1,190 lives a year. Heat stroke cases fell from 274 in 2010 to just 26 in 2018.
Malaysia does not need to start from zero. Kuala Lumpur, through the city council (DBKL) and C40 Cities, is already piloting the city’s first Heat Action Plan, including heat mapping, cooling centres, and shaded areas in vulnerable housing areas like PPR Beringin. Melaka has run a similar pilot since 2023.
Some of the best solutions are also the oldest: shade and greenery. Studies of Kuala Lumpur’s roadside trees have found they can make the air feel over a third cooler, with ground temperatures under thick tree cover dropping by more than 5°C.
In Penang, urban regeneration organisation Think City has shown this can be community-led too, funding green roofs and green spaces such as the Hin Bus Depot through small grants to residents and businesses rather than relying on big government projects.
A national plan should mandate tree canopy and shaded public space as standard requirements in urban planning, particularly around transport routes, markets, and informal settlements where outdoor workers and lower-income families spend the most time exposed to the sun. This is cheaper than air conditioning, and it keeps working during blackouts and grid strain, which heatwaves often cause.
We already have the know-how, what is missing is a national framework to bring it together and scale it up. We must stop the indiscriminate and brutal cutting of trees in Kuala Lumpur particularly, done without any thought for the protection they provide. What is needed is better maintenance and not knee-jerk drastic cutting after a weather related catastrophe!
That framework needs one clear owner, not eight ministries waiting for each other. The Natural Resources and Environmental Sustainability Ministry is best placed to lead, since it is already developing the National Adaptation Plan (MyNAP).
MetMalaysia’s heat warnings should not just warn the public, they should automatically trigger action across agencies, such as school guidance, outdoor work restrictions, and hospital readiness.
The Health Ministry should lead on the health side, including something no country’s heat plan yet does well: building heat-risk advice into routine antenatal care, and tracking pregnancy outcomes during heatwaves so we finally build the local evidence this field badly needs.
And the safety rules for workers need to stop being optional; employers need real obligations, and workers need real protection, on the days that matter most.
None of this is complicated. It comes down to coordination, enforcement, and attention; the same three things Malaysia has applied successfully to other public health threats before. We built the machinery to respond fast to floods and pandemics. We can build it for heat too. This is what the National Planetary Health Action Plan calls for, and it is urgent to implement it fully and immediately.
The heat is here, and it will grow worse every year we wait. What we choose to build for our outdoor workers, our elderly, our newborns, and the mothers carrying them will say a great deal about the kind of country we intend to be as our climate changes around us.
Prof Tan Sri Dr Jemilah Mahmood, a physician and experienced crisis leader, is the executive director of the Sunway Centre for Planetary Health at Sunway University. She is the founder of Mercy Malaysia and has served in leadership roles internationally with the United Nations and Red Cross for the last decade. She writes on Planetary Health Matters once a month in Ecowatch. The views expressed here are entirely the writer's own.
