Dear Readers!
Climate change is dramatically increasing the frequency and intensity of extreme heat events worldwide, and the millions of people who work outdoors are bearing some of the most significant burdens. From farmers in South Asia’s sweltering fields to construction crews in the Middle East and delivery drivers in American suburbs, outdoor labourers are being pushed to their limits by rising temperatures.
This surge in heat is not just an inconvenience – it is a matter of life, health, and livelihood. Over 70% of the global workforce (about 2.4 billion workers) now faces routine exposure to excessive heat, which has climbed more than 35% in the last two decades. Heat stress on the job is already claiming lives: each year, an estimated 19,000 workers die from heat exposure, and some 23 million suffer heat-related injuries or illnesses.
The article examines how climate-fueled extreme heat impacts outdoor workers across significant sectors and regions, drawing on the latest data and real-world stories to illuminate a growing crisis – and exploring what can be done about it.
There is no longer any doubt that a warming climate is turning up the heat and is driving more extreme heat. Heatwaves and prolonged high-temperature events have become more frequent, longer, and more intense due to climate change. The past few years have repeatedly broken temperature records; for example, data indicate that 2023 is virtually sure to be the hottest year on record, exceeding 1.5°C of average warming above pre-industrial levels.
Such unprecedented heat means many more people are being exposed. Even relatively temperate places are feeling the change. Heat-related mortality among older adults has increased by ~85% in recent decades, and extreme heat now causes more deaths annually in the United States than any other weather disaster.
Crucially, the impact of this heat is not evenly distributed. Physiologically, the very old and young are most vulnerable to heat illness, but exposure is also a key factor. That is why occupation has emerged as a significant risk determinant: outdoor and manual workers are highly susceptible to exertional heat stress. They have no choice but to bear the brunt of the scorching sun. As climate change continues to ratchet global temperatures, these workers are on the frontlines of a new era of heat extremes.
Extreme heat affects various jobs, but the sectors under siege have labour-intensive outdoor work and are especially at risk on this new and relatively hotter planet. Chief among them is agriculture, which employs millions of farmers, field labourers, and migrant farmworkers around the globe. Work on farms often involves long hours of heavy physical exertion under the open sun. Unsurprisingly, research shows that agriculture accounts for most of the global labour productivity lost to heat. Another primary sector is construction, where workers paving roads, building homes, or repairing infrastructure are often fully exposed to the elements.
Nevertheless, farmers and construction crews are not the only ones suffering from this unprecedented heat and warmer weather outdoors. Delivery and transport workers—couriers, postal carriers, and truck drivers—also suffer in extreme heat. Warehouse loaders, waste collectors, landscapers, and utility repair teams spend significant time outside. Even some manufacturing and mining operations occur in open-pit mines or outdoor facilities where high temperatures are an issue. Heat is a cross-cutting workplace hazard affecting a wide swath of jobs.
High heat exposure and high physical demand make these sectors particularly vulnerable. At extreme temperatures, people doing manual labour may need to slow down or take more frequent breaks to avoid heat illness, directly reducing productivity. In some cases, work stops during the hottest hours. As climate change brings hotter days than the pre-industrial times, the “workability” of midday hours shrinks.
According to the International Labour Organisation (ILO), by 2030, the global scale of the crisis will deepen, and the world will lose 2.2% of total working hours due to extreme heat, equivalent to 80 million full-time jobs disappearing. In economic terms, that is an annual global productivity loss of about USD 2.4 trillion. These estimates assume global warming is limited to 1.5°C; losses would be even more significant under worse scenarios.
Trends show we are heading in that direction. In 2022 alone, an estimated 490 billion labour hours were lost worldwide because of heat exposure. South Asia and West Africa will be the worst-hit regions, each seeing around 5% of total working hours wiped out by heat in 2030. In contrast, wealthier temperate regions such as Europe and North America are expected to have minimal average losses.
The injustice of this is stark. Lower-middle-income countries could lose about 4% of their GDP to heat stress by 2030. Many workers in these regions labour without the protections of formal labour laws or social safety nets.
The unprecedented heat has affected the regions globally. In South Asia, spring and summer temperatures have surged past 50°C in some areas. India is estimated to have lost about 259 billion labour hours annually due to rising heat and humidity. Up to 75% of India’s workers depend on jobs that expose them to extreme heat. Many continue working even at grave risk, with frequent reports of heatstroke deaths.
In the Middle East, workers in construction and oil fields toil in 45–50°C conditions. Despite midday work bans, hundreds of migrant workers in Qatar have died due to heat stress. Some countries have taken steps, like improving accommodations and experimenting with cooling technologies, but enforcement is inconsistent.
In the United States, summers are getting hotter, and heat waves are more intense than in earlier years. Heat now kills more Americans each year than any other weather hazard. Farmworkers and construction labourers are particularly vulnerable. A vital example is OSHA, which works on a national heat standard; some states have implemented heat safety regulations.
Latin America has seen chronic kidney disease linked to extreme heat in sugarcane workers. Across the region, farmers, street vendors, and labourers are struggling to work safely during more frequent heatwaves.
Outdoor work is widespread in Sub-Saharan Africa, and protections are few. West and Central Africa are expected to be among the most affected regions globally. Informal workers, especially market vendors and smallholder farmers, are particularly vulnerable.
Apart from the global impact, extreme heat has immense economic and health risks. These include heat exhaustion, heatstroke, dehydration, kidney injuries, cardiovascular strain, and increased risk of workplace accidents. Chronic exposure can lead to long-term health problems.
Economically, lost work hours translate to lost income. At the national level, heat stress can undercut productivity, reduce GDP, and exacerbate poverty. In sectors like agriculture, heat can also threaten food security. With such harsh impacts on humans and the planet, it is essential to work on potential solutions to reduce the stress from the climate crisis.
Many initiatives, such as policy initiatives, can become game-changers by mitigating the new ideas on climate resilience and adapting to those new ideas to reduce the stress and burden on the planet and humans.
Therefore, addressing the crisis requires both long-term mitigation and immediate adaptation, such as
- Mitigation: Reducing greenhouse gas emissions to slow global warming
- Policy: Implementing and enforcing labour protections for extreme heat.
- Scheduling: Adjusting work hours to cooler parts of the day.
- Cooling Measures: Providing shade, hydration, and rest breaks.
- Training: Educating workers and supervisors on heat illness prevention.
- Social Protections: Financial safety nets and heat-related insurance schemes
These are only potential solutions, and it is a long road to achieving climate resilience and adapting to a more sustainable lifestyle to ensure that the world becomes more liveable and breathable.
Thus, extreme heat is no longer a distant threat, and there is a call to protect all those who work under the sun. In short, outdoor workers worldwide face an alarming daily danger. These individuals are the backbone of global economies, yet their health and safety are often overlooked. Protecting them is not only a moral responsibility but also an economic necessity.
With stronger policies, innovative practices, and global cooperation, one can ensure that no one has to risk their life to earn a living under a hotter sky.
To conclude, I would like to sum up that the climate crisis is no longer knocking at our door—it has barged in and is reshaping the very foundation of labour across the globe. As rising temperatures threaten outdoor workers’ health, productivity, and dignity, our collective silence is complicity. These workers are not just statistics or silent figures under the sun—they are the hands that build, harvest, transport, and sustain the societies we take for granted.
When work becomes a gamble with life, it is no longer a job but a tragedy. We must shift from sympathy to systemic action, from acknowledgement to accountability. Investing in the safety and rights of outdoor labourers is not charity—it is justice. It is the bedrock of a resilient economy, a stable food system, and an equitable society.
If we ignore the furnace building beneath our feet, we will soon find our foundations crumbling. However, if we act—decisively, collectively, and compassionately—we can still protect those who work under the sun and, in doing so, protect the future of work itself. The question is not whether we can afford to act. It is whether we can afford not to.
Till we meet again…
Dr Prachi Jain