As heat waves intensify across Asia, community input is essential to passive cooling: "[It] only protects people if it reaches them where they are"

Officials in Southeast Asia have issued heat advisories in recent weeks in response to brutal heat waves. In Thailand, the Bangkok Metropolitan Authority warned people of "very dangerous" levels of heat, potentially exceeding 125 degrees Fahrenheit (52 degrees Celsius). Yet measures can be taken to address the devastating effects and improve equitable access to safer temperatures.

Among the potential solutions? Passive cooling strategies, defined by the Environmental and Energy Study Institute as "building technologies or features that lower indoor temperatures without the need for mechanical systems such as [air conditioning]," which rely on costly energy sources.

"We need to reframe passive cooling not as a discretionary expense, but as essential infrastructure that protects both human health and economic well-being," Gregory Wellenius, Director of the Center for Climate and Health at Boston University, told CG.

Rising global temperatures and intensifying heat waves are part of a changing climate and can disproportionately impact vulnerable populations, including older people and children. For pregnant people, exposure to extreme heat may be linked to serious health concerns, including cardiovascular stress. Prenatal exposure has also been associated with preterm birth, low birth weight, and stillbirth.

Women who rely on jobs outside, such as in agricultural production, may face these risks at higher rates. Case studies published in 2025 showed that street vendors exposed to extreme heat in Cambodia, Laos, and Vietnam also experience health risks — including impacts on mental health — and income loss, with women particularly vulnerable.

Those working in hot indoor spaces — such as in garment manufacturing mills or in care work in poorly ventilated homes — can face similar threats.

"These impacts translate directly into lost earnings and decreased economic output," Wellenius said. "Passive cooling investments represent prevention, investments that are expected to lead to fewer costly emergency interventions, hospitalizations, and lost labor productivity."

The ASEAN Center for Energy, an intergovernmental organization operating within the Association of Southeast Asian Nations, happened to release a "roadmap" aimed at promoting passive cooling strategies in early April, just as the recent heat waves spiked. 

Such cooling strategies can include efforts to prevent heat from entering a space, removing excess heat, modifying heat for comfort, and utilizing natural cooling sources. Passive cooling can look like architectural designs that provide solar shade, promote natural ventilation, optimize window placement, use green walls, and employ cool roofs. 

And according to Wellenius, these techniques work. "This approach recognizes that vulnerability to heat isn't just about physiological differences … it's fundamentally about where people are and what they're doing throughout the day."

These strategies also encourage designers, planners, and residents to come together to address the issue of extreme heat. Because different locations will require different solutions, community input is essential.

"The best approach is going to be very different in an urban informal settlement in Bangkok versus a rural agricultural community in Cambodia, and very different for market vendors versus agricultural workers who experience heat very differently," Wellenius said. 

He continued, "When communities are meaningfully involved in designing and selecting cooling strategies from the start, solutions are more likely to be culturally appropriate, technically feasible, and actually used. Passive cooling only protects people if it reaches them where they are."

Other infrastructural solutions to extreme heat include the integration of cleaner energy into cooling systems. In Cambodia, for example, the Asian Development Bank has helped to implement solar-powered cooling and irrigation at a pepper farm in Kep province. While improving cooling and water access, the adaptation has the added benefit of reducing reliance on costly and polluting fossil fuels.

As the ASEAN Center for Energy and Wellenius point out, meanwhile, even passive cooling strategies that don't require electricity or other mechanical infrastructure do require meaningful investment. The hope is that their effectiveness will prove their worth.

"I'm excited about how accessible and practical these strategies are, and especially about their potential cumulative impact," Wellenius said. "When multiple of these approaches are layered together, the combined effect on how people experience heat in their daily lives can be really significant."

In the meantime, health experts also recommend taking steps such as reducing time spent outdoors, spending time in cooled indoor spaces, wearing light clothing, and staying hydrated. As India prepares for what media outlets are calling its first major heat wave of the season, strategies of all scales are set to be critical.