WHO warns of risks of extreme heat in the workplace

Workers worldwide need better protection from extreme heat as climate change causes more frequent heatwaves – that’s the conclusion of a new report from the World Health Organization and the World Meteorological Organization.

The report says millions of workers are exposed to heat stress, which affects their health, and their performance. It calls for governments, employers, and workers to co-operate to develop adaptation strategies.

Although the WHO has warned many times of the health risks of extreme heat, this is its first report since 1969 specifically on heat stress at work.

The WHO’s director of environment, climate and health Rüdiger Krech says its findings should be a wake-up call.

“It is not just discomfort. It is a real health risk,” he told the BBC. “If you’re working in heat and your body temperature increases by, over a longer period, over 38C, then you are at risk of severe heat-related stress and stroke, kidney failure, dehydration.”

Adaptation is needed because heatwaves are no longer rare occurrences. The World Meteorological Organization says the last decade has seen the warmest temperatures on record, with 2024 being the hottest year ever.

In parts of Europe, temperatures of 40C (104F) and more are now not unusual. In Africa or the Middle East, they can rise to 50C. Average surface temperatures in the Mediterranean in July were the warmest on record at 26.68C, according to Mercator. This week the UK’s Met Office said this summer was on track to be one of the warmest since records began in 1884.

Heatwaves do not just damage health, the WHO warns, they also affect output. The new report shows that for every one degree temperature rise above 20C, productivity falls by 2%.

Meanwhile accidents increase. During Europe’s heatwave of 2023, Switzerland’s national accident insurance fund (Suva) estimated that when temperatures rose over 30C, workplace accidents rose by 7%. The causes, Suva said, included concentration issues as workers’ bodies struggled to adapt to extreme heat, and lack of sleep, again caused by the heat.

With construction and agricultural workers particularly at risk, some European countries are already looking at how they can adapt to make work safer during heatwaves. Last month, the Italian government signed an emergency decree, after agreeing a protocol with unions and bosses to stop people having to work during the hottest hours of the day.

In the Swiss cantons of Geneva and Ticino, construction was paused during the 2023 heatwave, a move welcomed by Switzerland’s largest trade union, Unia.

“Often on building sites they are already behind schedule, so they are really under pressure to keep working,” Unia’s Nico Lutz told Swiss TV.

“That’s why we need the building companies to take responsibility, and to say that above a certain temperature it’s irresponsible, it’s too hot to work, and we all accept that the work just takes a little longer.”

The WHO’s report, although it looks specifically at the workplace, also warns that the elderly, the chronically ill, and the young are at particular risk during heatwaves. That means schools as well as workplaces need to adapt.

In Germany, schools can declare “Hitzefrei”, when temperatures rise above a certain level. In the 1970s, 80s, or 90s, this often meant that, when the thermometer climbed above 30C, the school bell rang twice, and everyone could go home.

But that was when such temperatures were rare. Now 30C is increasingly common, and schools are reluctant to interrupt lessons so frequently. The WHO’s Rüdiger Krech understands why. “We’ve seen during Covid that stopping school… our school children are suffering still from it. Just thinking that the easy solution is we stop schooling, that is very often the most expensive on the children.”

When schools went back in Switzerland last week, temperatures across the country were well over 30C. The advice to teachers: take your classes to the swimming pool. But as Dagmar Rösler, head of the Swiss teachers’ association, told Swiss media, “We can’t do all our classes in the swimming pool – we’ve got things we need to teach.”

Ms Rösler, perhaps anticipating the WHO’s call for adaptation, called for school buildings, many of which are due for renovation, to include new ventilation systems, and even air conditioning.

“I just want people to remember that this is about making sure our children can learn in an environment that is comfortable for them,” she said. “And that our teachers can work in conditions that are bearable.”

The WHO/WMO report says adaptation needs to be done in consultation with everyone, from governments, to employers and workers, to local councils, and health and education authorities. Rüdiger Krech already has one suggestion that might appeal not only to school pupils in the UK, but to cash-strapped schools with little money for renovation.

“The school uniforms that you have in the UK, are they adapted to the heat waves? These are questions that we want people to consider.”

But there is no avoiding the fact that to adapt workplaces, schools, or even hospitals to cope with increased extreme heat will require investment. Many governments, especially in Europe, are refocussing their spending on defence, while climate change adaptation has slipped down the priority list.

Mr Krech warns this could be short sighted. “Just to think, I don’t have the money for all these changes. Well, think twice. Because if you need to stop producing, if you have your workers with severe health effects because of the extended heat waves, then think about the productivity losses that you have. To just think, I don’t have the money, so I’ll let it stay as it is, that’s perhaps the most expensive solution.”