In the global ready-made garment (RMG) industry, a sector employing millions in countries like Bangladesh, conditions are becoming increasingly perilous as climate change drives indoor factory temperatures to extreme highs. A recent groundbreaking study led by researchers at the University of Sydney delves deeply into the physiological impacts of heat exposure on garment workers and explores practical interventions to mitigate heat strain without resorting to costly and environmentally taxing air conditioning systems. Published in The Lancet Planetary Health, this research represents a critical intersection of climatology, occupational health, and sustainable industrial practice, offering a beacon of hope for a sector under intense pressure.
Bangladesh’s RMG industry is a colossal economic engine, with over four million predominantly female workers generating roughly 80 percent of the country’s export revenue. Yet, this financial boon comes at a steep human cost. Factory interiors regularly exceed 35°C and can climb as high as 40°C, environments characterized by oppressive humidity and poor ventilation compounded by heat generated from machinery such as irons and steamers. Workers often endure grueling shifts of up to 12 hours a day for six days weekly, confronting continuous thermal stress that undermines both their health and productivity.
The physiological toll of such conditions cannot be overstated. Prolonged exposure to extreme heat leads to dehydration and heat exhaustion, diminishing cognitive function and physical stamina — critical factors in tasks requiring precision and speed like sewing and ironing. Compounding this health risk is the systemic payment-by-piece wage structure, forcing workers to choose between slowing down for safety or maintaining pace and risking heat-induced illnesses. This scenario epitomizes a harrowing occupational trade-off exacerbated by climate change.
Professor Ollie Jay, the senior author of the study and Director of the Heat and Health Research Centre at the University of Sydney, articulates the urgency of the problem: as temperatures rise globally, heat-related illnesses among vulnerable populations such as garment workers become an existential threat. The study response involves not just documenting these dangers but testing scientifically validated cooling strategies that are affordable and scalable in real-life factory settings.
The research team engineered an innovative simulation of a typical garment factory in Dhaka inside a highly controlled climate chamber. This novel experimental design allowed for precise manipulation of environmental heat stress, reproducing extreme factory conditions without endangering participants. Within this controlled environment, the researchers evaluated the effectiveness of different cooling interventions, ranging from conventional air conditioning to simpler strategies like reflective insulated roofing, electric fans, and free access to clean drinking water.
Results from this randomized crossover trial yield compelling insights. Without any cooling intervention, workers exhibited a marked decrease in productivity, approximately 12 to 15 percent lower output attributable purely to the physiological burden of heat stress. This decline highlights the direct economic cost of inadequate working conditions in high-heat settings. However, when implementing sustainable cooling options that focus on personal, rather than ambient, heat mitigation — specifically electric fans combined with unrestricted hydration — much of this productivity loss was substantially regained.
The impact of modifying external factory design was equally striking. Installing an insulated, reflective white roof can reduce indoor air temperatures by approximately 2.5°C, which in turn lowers core body temperatures and heart rates while reducing dehydration risks. These physiological markers are critical indicators of heat strain, demonstrating that architectural adaptations can be a powerful tool in heat stress management for vulnerable workers.
An intriguing aspect of the findings is the gendered differential in cooling effects. Male participants displayed more pronounced benefits from the cooling interventions, suggesting that gender-specific factors — including varying metabolic rates, task assignments, and clothing types — influence how heat stress manifests and should influence mitigation strategies. Therefore, targeted adaptations considering these differences could enhance effectiveness and worker safety.
Dr. James Smallcombe, the lead author and postdoctoral fellow at the Heat and Health Research Centre, emphasizes that these findings do not merely provide theoretical benefit but offer practicable, low-resource interventions that factories can implement immediately. This is particularly salient as Bangladesh’s RMG sector seeks to reduce its greenhouse gas emissions by 30 percent by 2030, making heavy air conditioning usage an unsustainable path. Sustainable cooling presents a viable compromise balancing worker health, economic viability, and environmental stewardship.
This research carries profound implications beyond Bangladesh. Similar climatic challenges confront garment industries in India, Vietnam, and other low- and middle-income countries where the demand for apparel remains high, and thermal risks escalate. Addressing occupational heat stress with scalable solutions is crucial to safeguarding global supply chains, protecting worker health, and promoting ethical manufacturing standards.
The study also underscores the broader ethical and moral responsibility resting on the shoulders of fashion companies and factory owners alike. While air conditioning may seem a straightforward fix, it is neither financially accessible nor carbon-friendly for many factories. Prioritizing simple changes, such as providing unrestricted access to water and improving building materials to reflect and insulate heat, significantly aids worker wellbeing and aligns with global climate goals.
Additionally, the research was funded by the Wellcome Trust, which frames this challenge within the context of climate adaptation and public health resilience. Madeleine Thomson, Head of Climate Impacts and Adaptation at Wellcome, highlights that protecting workers from heat stress is a growing imperative. The study illustrates that adaptation strategies can simultaneously enhance health outcomes, support livelihoods, and reduce environmental impacts—a triple win for communities bearing the brunt of climate change.
The University of Sydney study presents a robust evidence base demonstrating that building design improvements coupled with hydration support form the cornerstone of effective climate adaptation in heat-vulnerable industries. As extreme weather events increase in frequency and intensity globally, these interventions represent proactive measures that advance occupational health security and industrial sustainability.
In sum, this research illuminates a critical nexus between climate change, labor rights, and sustainable industry evolution. By shifting focus toward accessible and economically feasible heat stress mitigation techniques, garment factories can safeguard their workforce, maintain productivity, and contribute to environmental goals concurrently. This pioneering study serves as a clarion call for stakeholders across sectors to innovate urgently and inclusively, transforming vulnerability into resilience amid a warming world.
Subject of Research: People
Article Title: Sustainable cooling strategies for workers in the ready-made garment factory industry in Bangladesh under simulated extreme heat: a randomised crossover trial
News Publication Date: 20-Oct-2025
Web References: http://dx.doi.org/10.1016/j.lanplh.2025.101317
Image Credits: Louise Cooper, University of Sydney
Keywords: Climate change, Physiology, Heat, Thermodynamics
