Coping with Heat and Productivity Loss in a Warming World

As the temperature climbs, productivity suffers due to heat stress. Last year, 2023, marks the hottest year on record.

According to NOAA, 2023 was the warmest year in the 174-year climate record, with average temperatures 1.18°C above the 20th-century average and 1.35°C warmer than the pre-industrial average.

Data from Copernicus, the EU’s climate monitoring service, show that 2023, at 1.48°C warmer than the pre-industrial levels, is close to breaching the Paris Agreement 1.5°C temperature limit.

A 2023 scoping review titled “Impact of climate change and heat stress on workers’ health and productivity” provides a comprehensive overview of existing research on how climate change, specifically increased temperatures and heat stress, affects workers’ health and productivity, highlighting that the global rise in temperatures is one of the major concerns in the 21st century.

The review identifies the various health outcomes due to heat stress, assesses the impact of heat on productivity in multiple occupations, and identifies the most vulnerable workers and the sectors to heat stress. Lastly, it provides recommendations on mitigation strategies and interventions to protect workers (Amoadu, Ansah, et al, 2023).

Health impacts from heat stress include exhaustion, heat stroke, dehydration, and the worsening of chronic conditions. Long-term health effects include cardiovascular, renal, and respiratory conditions due to prolonged exposure to heat.

Exposure to extreme heat events reduces cognitive and physical performance, which translates to economic losses, particularly in agriculture, construction, and manufacturing.

Vulnerable populations identified are outdoor workers, those in developing countries, and those without access to sufficient cooling or hydration.

The review highlights mitigation and adaptation strategies through workplace interventions such as modified work-rest cycles, improved hydration policies, and cooling technologies. Policy recommendations include regulations and standards for workplace temperature limits and mandatory breaks.

Furthermore, in developing countries, which are most vulnerable to heat stress, the review recommends that more effort be geared towards creating awareness about heat stress and its impact. Investing in training workers about heat stress and related illnesses is also necessary.

Between April and May 2024, Asia was hit by a deadly heatwave. According to the World Weather Attribution, climate change has made this deadly heatwave more frequent and extreme. From Israel and Syria in the West to Myanmar, Thailand, Vietnam and the Philippines in the East, large regions of Asia experienced temperatures well above 40°C for many days.

Heat stress caused by severe heat could reduce worldwide working hours by 2.2% by 2030.

A 2019 report from the International Labour Organization (ILO) explores the severe challenges heat stress poses due to climate change. The report projects that by 2030, heat stress will lead to the loss of 2.2% of total working hours globally, equivalent to 80 million full-time jobs. These job losses translate to substantial economic losses, estimated to increase from $280 billion in 1995 to $2.4 trillion by 2030​.

The report refers to heat stress as heat received more than the body can tolerate without suffering physiological impairment. Excess heat increases workers’ occupational risks and vulnerability; it can lead to heatstroke and, ultimately, even death.

Heat stress is a common problem in countries with higher working poverty rates, informal employment, and subsistence agriculture. In addition, disadvantaged and vulnerable population groups and communities – including indigenous and tribal peoples who are dependent on agricultural or coastal livelihoods – are at greater risk of suffering the adverse consequences of rising temperatures.

The report thoroughly examines the impacts of heat stress in all regions of the world, including Africa, the Americas, the Arab States, Asia and the Pacific, Europe, and Central Asia. It shows that the impacts are disproportionate across sectors and regions. The most vulnerable workers are in developing and emerging countries.

At least 79% of the total population of low-income countries lives in tropical areas, and climate change will exacerbate heat stress. Southern Asia and Western Africa are projected to be most affected by it. In 2030, they could lose 5.3%  and 4.3% of their working hours, equivalent to 43 million for Southern Asia and 9 million for Western Asia in full-time jobs.

The report identified the most vulnerable workers to heat stress as those who experience high levels of physical exertion, work in jobs that require heavy clothing and personal protection, and work in agricultural and construction jobs. Heat stress can also become a problem for industrial workers indoors if temperature levels inside factories and workshops are not appropriately regulated.

Increasing heat levels also affect jobs in refuse collection, emergency repair work, transport, tourism, and sports. Even office and desk tasks become difficult at high temperatures as mental exhaustion sets, including those working inside classrooms. Extreme heat affects students’ concentration, learning, and teachers’ performance.

The report emphasises the need for adaptation strategies, such as enforcing occupational safety and health standards, improving early warning systems for heat events, promoting social dialogue, and implementing labour market policies to mitigate the impacts of rising temperatures​. It also highlights the role of international labour standards, governments, employers and workers in reducing vulnerability to heat stress and promoting adaptation.

International labour standards, such as the Occupational Safety and Health Convention, 1981 (No. 155), treat heat stress as an OSH hazard that workers, employers, and governments should treat.

The Occupational Safety and Health Convention, 1981 (No. 155), and its accompanying Recommendation (No. 164) provide guidance for governments on how to develop and implement a national OSH policy that addresses heat stress, among other risks, per their individual needs and in consultation with the employers’ and workers’ organisations concerned.

The role of governments

Governments create a regulatory environment that facilitates behavioural change among employers and individual workers, guiding the development of measures to tackle heat stress at the workplace.

Examples of government regulations concerning heat stress include prescribing maximum temperatures to which workers may be exposed, specifying measures to prevent excessive heat levels, and stipulating that protective equipment should be used. In some countries like New Zealand and Canada, their government requires employers to provide a safe place of work and to identify and control risks and hazards.

The role of employers

Although the government sets regulations and standards, employers are responsible for providing a safe and healthy workplace and ensuring that working conditions conform to those standards. Health and safety regulations oblige employers to assess workplace risks and protect workers from recognised severe, heat-related hazards.

Employers can consider designing infrastructure and physical environments that protect workers from heat stress, such as providing air conditioning, misting and ventilation systems, and cool roofs. Outdoor workers sitting inside vehicles or large machinery can be protected from heat by air-conditioned cabins, but most outdoor workers have limited protection against hot air or the sun.

However, employers can set up shade canopies or move certain jobs, where possible, to naturally shaded. Another option is to increase mechanisation (especially in agriculture), which can reduce the physical demands and pace of jobs.

The role of workers

Workers also have an essential role in implementing adaptation measures to protect themselves. They can also take individual action to reduce their body temperature, for example, by drinking water frequently, shifting their working hours, taking breaks in cool and shaded areas, taking more breaks during particularly hot periods, wearing clothing that protects them from the sun while allowing airflow to the body, protecting one’s head with a hat if working outside, and being alert to the symptoms of heat exhaustion or heatstroke.

The use of a “buddy system” can also complement these measures. This system involves workers monitoring each other for heat stress symptoms like body temperatures, hydration, and heart rate or simply checking on them regularly. Workers should also inform their employers when and if they have concerns regarding their work environment.

Rising temperatures are becoming a serious health hazard, with many significant outcomes affecting all levels of society and sectors. Data from the review cited in the article and the ILO report can help create awareness of the dangers of exposure to extreme heat and how to address and reduce its impacts.