Researchers from the FAME Laboratory at the University of Thessaly, as well as from several other institutions, published The Impact of Workplace Heat and Cold on Work Time Loss in the Journal of Occupational and Environmental Medicine (February 2025). The study examined workers in Cyprus, Greece, Nicaragua, Qatar, Slovenia, and Spain throughout all seasons to assess how temperature affects work time. Researchers conducted field experiments with 376 manual workers from agriculture, construction, and tourism between 2016 and 2024
Human Level’s Take:
- Researchers have found that while extreme temperatures cause fewer lost work hours than previously thought, they likely affect more workers than expected.
- A study of manual labor roles in agriculture, construction, and tourism found that thermal stress from heat and cold reduces productivity—by about four hours in hot conditions and two hours in cold conditions. The least work time loss occurs at 18°C (64°F), with losses increasing for every degree above or below that point. Even workers in temperate regions are impacted, especially those who are physiologically vulnerable or not well-acclimatized.
- As climate change intensifies, this could have serious implications for workers, employers, and the global economy. Beyond health and safety risks, it may affect livelihoods, especially for piece-rate workers and smallholder farmers facing reduced yields due to thermal stress.
- What is the takeaway for companies? Factoring extreme temperatures into health and safety policies and procedures is a growing imperative for employers. Along with better cooling and heating practices, engaging directly with workers and unions can lead to innovative, cost-effective solutions—keeping worker well-being front and center
Some key takeaways:
- Why temperature matters at work: Research shows that ambient conditions (i.e., surrounding environmental factors like temperature, humidity, air pressure, etc.) have an impact on workers, affecting how they allocate time during a work shift between labour and non-labour activities like rest. Thermal conditions are even more impactful in climate-vulnerable industries like agriculture, construction and tourism, where manual workers are exposed to both heat and cold stress. The researchers point out that impacts on worker productivity have effects resounding beyond the workplace, potentially impacting living conditions, weakening food security due to reduced yield and having spillover effects on the global economy. What’s more, as climate change intensifies and causes more extreme temperatures, thermal stress is likely to increase and will become an ever more urgent issue for workers and employers.
- Key findings: Researchers found that the least work time loss among the workers studied occurs at 18°C (64°F), and increases for every degree above or below this optimal temperature. In practice, this can equate to around four hours lost due to hot workplace conditions and around two hours lost in cold workplace conditions (out of an eight-hour shift). The study also points out that the experiment focused on workers who are experienced in their work and already acclimatised to local conditions; however, workers who are less experienced and/or not acclimatised may be even more vulnerable to temperature impacts. In addition, workers who are more susceptible to physiological heat strain (e.g., due to health conditions, age, etc.) are more likely to face loss of work time as thermal stress increases.
- Implications for policies and workplace practices: The study shows that, although actual working time lost is less than previous studies show, it is also much more widespread than previously thought. This means that thermal conditions are not only a problem in very hot workplaces and countries but are a risk even in more temperate environments. The authors point out that this has significant implications globally because “it suggests that billions of people are currently working in temperatures not optimal for work, but this goes unnoticed.” As climate change makes extreme temperatures more common in new parts of the globe, this is poised to become an even bigger problem for workers, employers and policymakers. The authors recommend adopting their model of calculating work time lost — the Workplace Environmental Labor Loss or WELL functions — to accurately assess the impact of workplace heat and cold on work time loss.
