Garment workers face some of the most precarious working conditions in the world and are increasingly at risk from extreme heat stress caused by climate change. A new University of Sydney-led study reveals how simple, affordable interventions could offer critical protection to those working in dangerously hot conditions. Published in The Lancet Planetary Health, the study identifies low-cost and scalable strategies that can reduce heat stress and protect worker productivity in Bangladesh's ready-made garment (RMG) sector – a $45 billion industry employing over 4 million people, most of them women. It represents 80 percent of Bangladesh's export revenue and is the fourth-largest garment exporter in the world.
In Bangladesh's RMG factories, indoor temperatures often soar above 35°C and can reach as high as 40°C. Production halls are typically hot, humid, and poorly ventilated, with the constant use of heat-generating machinery like irons and steamers making the air thick and stifling.
Workers spend up to 12 hours a day, six days a week , in these conditions which, over time, can take a considerable toll, causing dehydration, heat exhaustion, and a noticeable drop in energy and concentration, putting workers' health and wellbeing at serious risk. Most workers are paid by the piece, creating a difficult trade-off: slow down to stay safe in the heat – and earn less – or maintain speed and risk serious illness.
"Garment workers in Bangladesh already endure some of the most precarious and grueling conditions in the world. With rising temperatures, it's only getting worse," said the study's senior author, Director of the Heat and Health Research Centre at the University of Sydney, Professor Ollie Jay. "Without immediate, scalable, and affordable cooling solutions, millions face a serious and growing risk of heat-related illness, exhaustion, and long-term harm."
To address this, Professor Jay's team looked at the effects of various cooling alternatives to air conditioning on worker heat strain in a simulated Bangladesh garment factory inside a climate-controlled chamber, replicating the hottest conditions recorded inside a typical factory in Dhaka.
They tested simple cooling interventions such as insulated reflective roofs, electric fans, and free access to drinking water, and benchmarked them against air conditioning and no cooling at all.
They found:
Without cooling interventions, heat stress reduced work output by around 12 to 15 percent. These losses were partly recovered through the team's sustainable cooling strategies, which prioritised cooling the individual instead of altering the surrounding environment, such as using fans and drinking water.
A 2.5°C indoor temperature reduction from an insulated, reflective white roof lowered core body temperature, heart rate, and dehydration risk.
Electric fan use combined with access to drinking water delivered similar benefits, reclaiming much of the heat-related productivity loss seen in high-intensity tasks like ironing.
Cooling effects were more pronounced in male participants, highlighting the importance of reconsidering gender-specific tasks and clothing in heat mitigation strategies.
"The findings offer practical, scalable solutions for factory owners seeking to improve working conditions without relying on air conditioning, which remains economically and environmentally unsustainable," said lead author Dr James Smallcombe, a post-doctoral research fellow in the Heat and Health Research Centre. "With Bangladesh's RMG industry targeting a 30 percent cut in greenhouse gas emissions by 2030, these low-resource options could offer a viable path forward for a sector under increasing pressure from both global demand and a changing climate."
"The fashion industry has a moral and ethical imperative to reduce heat stress for workers and ensure basic provisions, such as access to clean drinking water. That includes both companies and factory owners. While air conditioning may help, it should not be seen as a silver bullet; instead, sustainable, affordable cooling solutions should be considered to protect workers' health and wellbeing," said Dr Smallcombe.
The full results suggest that improving building design and supporting worker hydration could become key pillars of climate adaptation in global supply chains, protecting both workers and business continuity.
The Wellcome Trust funded the research. Dr Madeleine Thomson, Head of Climate Impacts & Adaptation at Wellcome, said: "Factory workers in sectors like the garment industry who are working in hot conditions are increasingly at risk from extreme heat stress caused by climate change.
This study highlights that without cooling interventions, workers face serious health risks and reduced productivity - impacting both individual and business earnings. Yet, it also shows that even small, science-based changes can lead to significant improvements in health, livelihoods, and the environment – a triple win for communities.
"Adaptation isn't just about surviving climate shocks – it's about building resilience and enabling communities to thrive. Leaders at every level - regional and national - must act now to deliver solutions that protect health and unlock opportunity."
While the environmental conditions reflected those observed in Bangladesh, the findings are also relevant to other countries with large ready-made garment industries, such as India and Vietnam, where extreme conditions are also common.
Bangladesh is widely recognised as one of the world's most climate-vulnerable countries, facing heightened risks from sea-level rise, extreme weather, and heat stress. Its garment industry accounts for 80 percent of Bangladesh's export revenue and is the fourth-largest garment exporter in the world.
