In Chennai, a multi-component heat stress prevention plan was introduced at a brick kiln, including shaded work areas, improved sanitation, and electric vehicles to reduce manual labour. The plan led to a 57 per cent increase in productivity and significant improvements in worker health and safety.

The International Labour Organization (ILO) has reported a significant increase in the number of workers globally affected by heat stress, an issue that poses severe health risks and potentially deadly outcomes. The ILO’s latest report, titled “Heat at Work: Implications for Safety and Health,” highlights that extreme heat is not just an environmental concern but a growing workplace hazard affecting millions of workers worldwide.

The report underscores that heat stress, often referred to as a “silent killer,” can lead to immediate health crises such as heatstroke and, in extreme cases, death. Long-term exposure to excessive heat can also result in chronic health conditions affecting the heart, lungs, and kidneys. The ILO’s findings paint a concerning picture of how increasing temperatures are endangering workers in various regions, with some areas experiencing unprecedented levels of heat stress.

According to the report, workers in Africa, the Arab states, and Asia and the Pacific are experiencing the highest levels of heat exposure. Specifically, 92.9 per cent of the workforce in Africa, 83.6 per cent in the Arab states, and 74.7 per cent in Asia and the Pacific are affected by excessive heat, surpassing the global average of 71 per cent reported in 2020. Notably, Europe and Central Asia have seen the most rapid increase in heat exposure over the past two decades, with a 17.3 per cent rise from 2000 to 2020, nearly double the global average increase.

Heat stress year-round

The Americas and Europe and Central Asia are also witnessing significant rises in heat-related workplace injuries. Since 2000, injury rates in these regions have surged by 33.3 per cent and 16.4 per cent, respectively. This increase is partly attributed to rising temperatures in areas where workers are less accustomed to extreme heat.

The ILO’s report reveals that in 2020 alone, 4,200 workers died due to heatwaves, while a staggering 231 million workers were exposed to such conditions—a 66 per cent increase from 2000. However, the report emphasizes that the majority of heat-related injuries occur outside of heatwaves. Approximately 90 per cent of workers are exposed to excessive heat throughout the year, and 80 per cent of heat-related injuries occur during non-heatwave periods.

The ILO Director-General Gilbert F. Houngbo stresses the urgency of addressing this issue. “As the world continues to grapple with rising temperatures, we must protect workers from heat stress year-round,” he asserts. “Excessive heat is creating unprecedented challenges for workers worldwide, not only during heatwaves but throughout the year.”

Financial impact

The financial impact of heat stress is substantial. The ILO estimates that improving safety measures to combat heat stress could save up to $361 billion globally in lost income and medical expenses. Low- and middle-income economies are particularly hard hit, with the costs of heat-related injuries reaching up to 1.5 per cent of national GDP.

“This is not only a human rights and workers’ rights issue but also an economic one,” Houngbo adds. “Middle-income economies are bearing the brunt. We need year-round heat action plans and legislation to protect workers, alongside stronger global collaboration to harmonize heat stress assessments and interventions.”

The UN Secretary-General, Antonio Guterres, echoes this sentiment, emphasizing the global nature of the crisis. “If there is one thing that unites our divided world, it’s that we are all increasingly feeling the heat. We must rise to the challenge of rising temperatures and step up protections for workers, grounded in human rights.”

The ILO report also explores legislative measures across 21 countries to identify effective heat safety strategies. It builds on a previous report released in April, which highlighted the severe health risks of excessive heat affecting an estimated 2.4 billion workers. The April report revealed that excessive heat alone contributes to 22.85 million occupational injuries and 18,970 deaths annually.

India: Brick kiln workers

In India, recent studies have shed light on the severe impacts of heat stress on workers. A 2024 study of 800 pregnant women in India found that 47 per cent were exposed to excessive heat at work, leading to higher maternal body temperatures and moderate dehydration. Additionally, a study funded by India’s Department of Science and Technology focused on workers in brick kilns in Chennai. It found that 53 per cent of workers faced heat stress levels exceeding recommended limits even during cooler periods, with 83 per cent reporting adverse heat-related symptoms.

India has implemented measures to address heat stress through its Factories Act of 1950, which mandates that the wet bulb temperature in workrooms should not exceed 30°C. The National Disaster Management Authority, in collaboration with the Ministry of Home Affairs, has also developed guidelines for managing heatwaves, emphasizing worker education, proper hydration, regulated work schedules, and necessary medical facilities.

In Chennai, a multi-component heat stress prevention plan was introduced at a brick kiln, including shaded work areas, improved sanitation, and electric vehicles to reduce manual labour. The plan led to a 57 per cent increase in productivity and significant improvements in worker health and safety.

These measures serve as a model for addressing heat stress in various industries and highlight the importance of proactive interventions to protect workers. As global temperatures rise, the need for comprehensive heat stress management strategies becomes increasingly critical to safeguard worker health and ensure workplace safety.