Heat reduces worker productivity — who is affected

The International Labour Organization warns that summer heat is already reducing worker performance, with consequences for health and the economy. The report was published on 11 August 2026 and lists the temperature thresholds at which work capacity falls and the sectors most affected.

According to the report, temperatures above 24–26 °C are associated with reduced productivity, and at 33–34 °C a worker can lose up to 50 percent of their work capacity. Exposure to excessive levels of heat can cause heat stroke and in some cases be fatal. Workers both outdoors and indoors are at risk.

Which occupations are most vulnerable and what helps

Particularly exposed are jobs that require greater physical effort or are outdoors: agriculture, construction, waste collection, transport and tourism, while industrial workers in indoor settings can also be at risk. Measures listed for mitigation include flexible working hours and more frequent breaks.

Jasminka Petrushevska, a general practitioner, warned about emergency signs and preventive measures: "Productivity falls because at high temperatures blood pressure decreases, muscles relax, and concentration also decreases. If people feel any symptoms, they should not wait; if they become weak, action should be taken immediately. They should follow the recommendations. Eat light food, take in fluids, and the chronically ill are particularly at risk."

The report also points to impacts on mental functions: "brain fog" may occur, with reduced ability to focus and concentrate during heat waves. "Of course heat affects people. Summer as summer is very hot, especially these days. People are indeed a bit more anxious, and when we enter September they become more stable. Summer also affects mental health," said Ildita Biljali, psychologist.

Economic losses due to heat stress at the workplace were estimated at US$280 billion in 1995 and, according to projections, will rise to US$2.4 trillion in 2030. The International Labour Organization warns that heat stress is more frequent in countries with a deficit of decent work; the most affected subregions will be South Asia and West Africa. Under a global warming scenario of 1.5 degrees by the end of the century, heat stress in these two subregions would lead to losses of 5.3 percent and 4.8 percent of working hours by 2030 — corresponding to roughly 43 million and 9 million full-time jobs, respectively.

The report emphasizes that targeted preventive measures, employer adjustments and public policies are needed to protect vulnerable groups of workers as temperatures rise. The time for decisions on scheduling, hydration, cooling and medical monitoring is limited if reductions in human and economic losses are to be achieved.

Photo: press material from the event