“SHE IS HOT” exclaimed a male student, gaining immediate attention in my scientific lab. They clamoured to his monitor only to be disappointed to see that their colleague was only gawking at the heat map of Penang heralding extreme temperatures. The signal they should have picked up is that extreme temperatures will come to be our new normal.

Heatwaves are technically prolonged periods of excessively high temperatures, significantly above the normal averages for a region and often accompanied by high humidity, especially in tropical areas like Penang. These extreme weather events can last from several days to several weeks, posing serious health risks such as dehydration, heatstroke and the exacerbation of chronic health conditions. Beyond immediate health impacts, heatwaves strain the infrastructure, reduce air quality, impact water supplies and disrupt daily life and the economy. As climate change accelerates, heatwaves will become more frequent, intense and longer-lasting. Communities will simply have to adapt and mitigate these effects.

During these periods, the very fabric of daily life gets altered. Mornings, once the best time for a brisk walk or jog along the beach, become a race against the rising mercury. By midday, the heat becomes unbearable, smothering the city. Streets, usually bustling with activity, take on a deserted look as people seek refuge indoors. Everywhere air conditioning offers a respite from the relentless heat.

The nights offer little relief. The promise of cooler air after sunset remains unfulfilled, with the heat lingering, thick and stubborn, refusing to dissipate. Sleep becomes elusive, as even the slight breeze from a fan does little more than push the hot air around. The constant hum of air conditioners from neighbouring buildings serves as a stark reminder of the battle we all wage against the heat.

The physical toll of these heatwaves is palpable. Even simple tasks become Herculean efforts. The body struggles to cope, with sweat beads forming at the slightest exertion and yet offering little relief. There is a constant thirst, reminding us that dehydration is a real danger, not just a discomfort. Heat-related illnesses loom large, especially for those among us who are vulnerable—the elderly, the young and those with pre-existing health conditions.

But it is not just a physical challenge; it is a mental and emotional one as well. The heat can feel claustrophobic; we are trapped in our homes, our routines disrupted and our social interactions limited. The vibrant community life that defines our city, from outdoor markets to festivals, is put on hold. There is a collective sense of waiting, of holding our breath for the heatwave to pass so we can return to our lives.

The infrastructure struggles too. The demand for electricity surges, a testament to everyone’s reliance on air conditioning. Water shortages remind us of the preciousness of this resource, particularly when dehydration threatens. Roads and buildings, especially weathered heritage constructions that were not built to withstand such extremes, show signs of wear, adding to the sense of a city under siege.

As these heatwaves become more frequent and intense, there is now a growing realisation that this may be our new normal. The challenges we face are a preview of the future, prompting us towards adaptation and resilience. It is a stark reminder of our vulnerability to nature’s whims and a call to action to mitigate the impacts.

Living through these heatwaves is a personal experience of climate change, one that leaves an increasingly indelible mark on our lives and our city.

High Humidity Makes it Worse

Coastal cities like Penang tend to experience high relative humidity in tandem with the heat wave. Relative humidity (RH) is a measure of how much moisture the air is actually holding compared to how much it can potentially hold at a given temperature. The concept is crucial because the capacity of air to hold water vapour increases with temperature. Expressed as a percentage, RH is a way to describe the saturation level of the air with water vapour. The average RH for Penang is 73%—lowest in February (69%) and highest in October (73%). The value tends to be high for coastal cities in the tropics. It feels warmer when the relative humidity is elevated. High RH at high temperatures makes it feel hotter than it actually is because our sweat evaporates less efficiently, hindering the body’s ability to cool itself. Understanding this may improve our resilience and raise livability in coastal areas.

Infrastructure Under Strain

Much of the urban landscape of Penang also experiences the “heat island” effect—a phenomenon where higher built-up areas and human activities become significantly warmer than their rural surroundings. This effect can amplify the impact of heatwaves, making cities even hotter and less bearable.

A study by Think City pointed to the heat island effect and increasing temperatures in Penang between 1988 to 2020, indicating high temperatures in George Town with particular peaks in ground temperatures at KOMTAR, Jelutong and Batu Lancang. Cooler areas are found in Balik Pulau and Seberang Prai.

Dark surfaces such as roads and tarmacs, exposed high-rise concrete buildings encased in glass, and the lack of greenery increase temperatures, especially in urban settings. In megacities of the world, temperatures can rise between 0.1°C–3°C higher than the surrounding rural landscape. In KL, this urban heat island effect has been seen to raise its temperature by 4°C–6°C.

Air Conditioning a Double-edged Sword

While we may look to air conditioning as a panacea for tolerating heatwaves, its actual application may raise more complex issues—and as the temperature rises, be more limiting. We depend now on air conditioning as the necessary adaptation to rising temperatures. Indeed, it lowers indoor temperature and even reduces humidity, and keeps homes and workplaces cool. But there is a dark side to air conditioning.

Air conditioners consume a significant amount of energy, contributing to higher greenhouse gas emissions. In areas including Malaysia where electricity is primarily generated from fossil fuels, the environmental impact can make widespread air conditioning use more problematic. The paradox of air conditioning is that while it provides relief from the heat, it also contributes to global warming through high energy consumption and the potential release of refrigerants that are powerful greenhouse gases, altogether exacerbating the heat problem.

With the rising cost of electricity and higher needs during peak demand times, steep additional charges will apply. Even now, running air conditioning can become prohibitively expensive, especially at lower temperature settings or when used continuously.

Most residential and commercial air conditioning systems are designed to maintain a comfortable indoor environment under specific temperature ranges. During extreme heatwaves, where outdoor temperatures exceed these design parameters, air conditioners may struggle to cool spaces effectively.

In extreme temperatures, the electricity demand can outpace supply, leading to brownouts or blackouts. During such times, reliance on air conditioning becomes not just prohibitive but impossible, highlighting the need for alternative cooling strategies to be put in place for Penang.

In any case, not everyone has access to air conditioning, which raises concerns about equity and vulnerability during heatwaves as well.

The Selective Impact of Heatwaves

Heatwaves affect the population differently. This inequality in impact will affect labour and human productivity in various ways. Wealthier individuals often have better access to air conditioning and can afford to run it longer, while economically disadvantaged people might not have this luxury at all, raising their vulnerability. Traditional adaptations to heat, such as naturally ventilated housing with large windows and raised roofs have long been abandoned in favour of cheaper building alternatives in cities where accommodation is more congested, leading to maladaptation to temperature rise.

Those living in poorer housing, often without adequate insulation or ventilation, suffer more during a heatwave. Poorer urban neighbourhoods may be crowded and tend to have fewer trees and green spaces.

Many who work in agriculture, construction and other outdoor jobs are continuously exposed directly to the sun, raising the risk of heat-related threats. Their productivity can drop due to their need for more frequent breaks and the overall slower pace of work in extreme temperatures. Farmers and fishermen, for instance, cannot work at optimum capacity in the extreme heat. Such a negative shock on these sectors will impact our food security.

The elderly may have a reduced ability to regulate body temperature and may not recognise the signs of heat stress, while schoolchildren may be more active and not as conscious of hydration needs, making these groups particularly susceptible during heatwaves. In addition, we may ask—how many of our schools can afford air conditioning units to confront the heatwave? Individuals with heart problems, obesity or respiratory issues are also at a higher risk, as their conditions can be exacerbated by the heat, leading to a greater need for medical care.

In Malaysia, the stark reality of climate change and rising temperatures stands to deepen poverty, particularly among those whose livelihoods are intricately tied to climate-sensitive sectors such as agriculture, fishing and the informal urban economy. The vagaries of weather patterns exert a disproportionate strain on these individuals as unpredictable rainfall and intensifying heat threaten crop yields and disrupt natural ecosystems. The risk of wildfires is heightened during periods of intense heat.

The urban poor, often engaged in casual labour that lacks the security of formal employment, find themselves on uncertain ground. As temperatures rise and extreme weather events become more common, their already precarious position becomes even more tenuous, pushing those hovering just above the poverty threshold into deeper hardship. The implications are clear: without intervention and adaptation strategies, climate change will alter the socioeconomic landscape of Malaysia, with the burden falling heaviest on those least able to bear it.

What Can We Do About It?

The Climate Risk Country Report for Malaysia done by the World Bank Group states that “the current median probability of a heat wave (defined as a period of three or more days where the daily temperature is above the long-term 95th percentile) now is very low, around 2%, but under the modelled prediction for the future this number increases dramatically to 93% by 2090”. This means that we are on track towards a very warm future indeed. Let us not find comfort in the figures being for the “far future”; we have already managed to break the heat record recently, with Chuping in Perlis leading the way.

In Penang, the hottest months are usually in April, May and June. Acknowledging this trend and knowing how we should prepare for the future is central to how we are to survive the rising heat. There are several approaches and many of these are still within our capabilities to implement. Let us consider the following in preparation for the oncoming temperature rise.

Heat Resilient Urban Infrastructure

As cliché as it may seem, green infrastructure is probably the cheapest alternative for heat resilience. Planting trees and creating green spaces can provide shade and cooling through evapotranspiration. Car parks, rooftops and roads can be placed under green shades of vegetation through tree plantings. We may improve city life by having traffic-free and pedestrian-friendly walkways connecting our major urban conduits and homes. Surely the George Town World Heritage Site can be elevated with verdant greenery and shade.

Building with materials and designs that naturally reduce heat absorption and improve energy efficiency will be critical. Using reflective surfaces on buildings and roofs to reflect sunlight and absorb less heat will reduce indoor temperatures and energy bills. George Town’s urban layout can certainly be improved to enhance airflow and help reduce the urban heat island effect.

In parts of the world, cheap solutions are already employed to reduce heat in living spaces. In India, there are experimentations with reflective paints applied to traditional corrugated roofs to cool homes. We can learn from these novel approaches to cooling.

In other locations, adaptive landscaping has helped in heat reduction as well as in providing secondary advantages to the heat problem. This includes the application of rooftop gardens and vertical farming to cool buildings with the added advantage of providing food to the tenants.

The Penang State Government’s plan to plant 500,000 trees across the state by 2030 is a good start, as are the planting of mangrove tress along the coastline.

Energy and Water Efficiency

Developing renewable energy and raising efficiency in water use are also key. Interest in investing in smart grid technology and renewable energy sources has grown. In the case of solar energy, while deployment costs remain relatively high, they have gone down significantly compared to the last decade. Capitalising on this, large-scale utilisation has started at the Universiti Sains Malaysia, for example, where rooftop solar panels are applied to almost all its buildings including the car parks. This is to encourage the transition to green energy.

As the temperature rises, water supply will be an issue. While the price of water in Penang is among the cheapest in the country, this cannot last as freshwater becomes scarcer. Penang has already increased her water tariffs in anticipation of high water demands and its forecasted limited supply. Fresh water will be an expensive commodity in the future and new alternatives in water conservation need to be practised. The use of grey water is one significant source of alternative supply. Wastewater can be treated and recirculated for diverse uses in the city and industries. Moreover, in many housing areas now, rainwater collection from rooftops to support the main supply and reduce water demand from the grid has proven effective and should continue to be encouraged.

Our earlier preparation in the protection of catchment areas as natural water storage spaces has been shown to pay dividends, especially during times of droughts that coincide with the heatwaves. They not only reduce risks of flooding during the rainy season but also improve water security during periods of high temperature and droughts.

“A Change Is Gonna Come”

There is a need to establish a system that alerts the public to impending heatwaves. Such a system can be supported with community outreach to promote heatwave readiness and adaptation. It has also become abundantly clear that we will need to adjust our lifestyles to a hot future.

As heatwaves become more frequent, Penang will have to adapt to survive. It is going to getting hotter and more humid. As I write this, a tune echoes in my head. I hear the crooning blues singer, Sam Cooke, putting it succinctly: “It’s a long time coming. But I know a change is gonna come… oh yes it will.”

Perhaps in acknowledging this, we can then plan and prepare ourselves, ready our homes and educate our children about their future.