When is it too hot to work?

Euronews

19-07-2025

From Italy's farms to Germany's warehouses and beyond, soaring summer temperatures pose serious health risks to workers across Europe.
Heat stress can cause heat exhaustion, heat stroke, and death, even hours or days later. The strain the body puts on itself trying to keep cool can also cause kidney problems and worsen heart disease, respiratory issues, and mental health.
These risks came to the fore during brutal heatwaves earlier this summer, when a 51-year-old street cleaner in Barcelona collapsed and died hours after finishing her shift. Spanish authorities are investigating whether the heatwave caused her death.
Unlike other environmental health hazards such as air pollution, there are no uniform rules on heat exposure for workers in the European Union, leaving member countries to make their own laws.
But when is it actually too hot to work – and what can workers do to protect their health during heatwaves?
Understand the risks
High temperatures are not the only health risk during heatwaves. The Wet Bulb Globe Temperature (WBGT) is considered a better signal of heat stress for physically active workers because it takes into account heat, humidity, wind, and sunlight.
The WBGT includes four threat levels: low, elevated, moderate, high, and extreme. Depending on the region, temperatures above 29 to 32 degrees Celsius are considered extreme threats to workers' wellbeing, raising the risk of heat illness significantly.
Extreme heat is more dangerous for people working outside in physically demanding jobs, for example construction workers, agriculture workers, and emergency services.
But indoor employees – including those who work in offices – can also face risks, particularly if they are in poorly cooled or ventilated buildings, according to EU-OSHA.
Globally, extreme heat kills nearly 19,000 workers per year, according to the International Labour Organization (ILO), and the EU has seen a 42 per cent increase in heat-related workplace deaths since 2000.
Pay attention and take action
Many people may not realise they are at risk of heat stress, particularly if they are young and otherwise fit, warned Alessandro Marinaccio, research director of the occupational and environmental epidemiology unit at the nonprofit National Institute for Insurance against Accidents at Work (INAIL) in Italy.
'There is a lack of awareness about the risk for the health of workers due to occupational exposure to extreme temperature,' Marinaccio told Euronews Health.
His team developed a tool to map daily risk levels for workers in Italy, depending on how physically strenuous their job is and whether they work in the sun or the shade.
Health experts say workers should also pay attention to their physical symptoms.
'Workers should be mindful of elements such as dizziness, fatigue, headache, nausea, muscle cramps, fainting, and confusion,' said Ignacio Doreste, a senior advisor at the European Trade Union Confederation (ETUC), which represents labour groups.
If you are feeling symptoms of heat stress, stop working, drink water, remove unnecessary clothing, and sit down in a cool, shaded area. If you cannot cool down within 30 minutes, seek emergency medical care.
Know your rights
Several EU countries have rules to protect workers from heat stress, including Germany, Slovenia, Hungary, Belgium, Cyprus, Greece, Spain, France, and Italy.
In France, for example, employers must make fresh drinking water available to workers and adapt their workplaces and working hours to protect them from extreme heat.
In parts of Italy, the government banned outdoor working during the hottest hours of the day during the last major heatwave in July.
Generally, countries with heat-related laws set work limits of around 29 to 30 degrees Celsius for high-intensity work, 30 to 31 degrees for moderate work, and 31.5 to 32.5 degrees for light work, according to the ILO.
The EU also mandates that employers protect workers' health and safety from occupational risks overall, though there is no specific legislation on heat stress.
Across the EU, 'whenever a worker is facing a threat to his own physical integrity, they have the right not to work,' Doreste told Euronews Health.
But 'enforcement is extremely needed,' he added, especially because 'diseases related to occupational heat are commonly underreported'.
The ETUC has called for new laws to protect EU-based workers during heatwaves, including the right to medical examinations and the right to skip work without consequences if an employee believes working in extreme heat will put them at risk.
If you are unsure about your rights during a heatwave, check your work contract or consult with your company representatives or trade union.