For years now, one heat record has been breaking another. Temperatures of up to 40 degrees Celsius are expected this coming weekend. Such extreme temperatures serve as a warning sign: cities, in particular, whose built environments amplify the effects of climate change, are especially vulnerable to heat. Asphalt, concrete, and dark facades absorb heat, release it gradually throughout the night, and thus exacerbate the strain on the population. Extreme temperatures can be particularly dangerous for children, older adults, people with chronic illnesses, and those who work outdoors. A sustainable adaptation measure would be the widespread use of heat-reducing plants, but urban greening must urgently proceed at a faster pace to be effective in the coming years. Environmental organizations such as Greenpeace and WWF are therefore calling for a greening initiative to combat heat, as well as the removal of impervious surfaces in heavily built-up areas.

 

Special Budget for Heat Protection

WWF Austria is calling for a special budget of one billion euros for cities and municipalities to protect against heat, drought, and water stress. The federal and state governments are to use the funds primarily to support the redevelopment of heavily impervious areas, for example through the removal of impervious surfaces, greening, the creation of near-natural water bodies, and increased water retention. In the medium term, the pending national renaturation plan, in particular, must be adequately funded so that such measures can be implemented nationwide.

“More nature is the most effective protection against heat. Open ground, healthy trees, living bodies of water, and intact wetlands absorb water like a sponge and provide noticeable relief from the heat in everyday life.”

WWF expert Joschka Brangs

 

The finance minister and the state governors should therefore quickly begin discussions on a special budget for this purpose.

The WWF recommends three policy priorities for this:

First, we need binding land-unsealing targets and incentives for cities and municipalities.
Second, trees must be better protected, and new urban trees must be planted with sufficient root space.
Third, there needs to be more restoration of rivers, floodplains, wetlands, and forests. These natural areas store large amounts of water, cool their surroundings, and reduce the damage caused by heat and drought to both people and nature.

“Heat protection must not be limited to behavioral tips. What matters most is how we design our towns and landscapes. Asphalt wastelands, dry soil, and paved-over streams are further fueling the crisis. That’s why we need more open spaces, more shade, and more natural water reservoirs,” says Brangs.

According to estimates by the European Commission, every euro invested in renaturation generates an average social return of 12 euros, in part due to positive effects on health, safety, and crisis preparedness.

 

Greenpeace Analysis: Severe Heat Stress; Green Spaces Are Crucial

Greenpeace has examined heat stress in Austria's cities in relation to their proportion of green space. An analysis of the country's 80 most populous cities shows:

In 2025, six cities experienced very high heat stress,
and another 21 experienced high heat stress.
Some of the city centers studied are already well equipped to cope with urban heat thanks to their abundant green spaces, while others urgently need to become greener.

The latest Heat Check is based on a large-scale analysis of satellite data (https://act.gp/4w06pOg), in which Greenpeace examined the green spaces in the 80 largest cities with populations of 10,000 or more. Combining this data with the number of hot days in the previous year now highlights where the need for green spaces is most acute.

Cities in southern and eastern Austria experienced a particularly high number of hot days last year. Wolfsberg, St. Veit, Völkermarkt, Vienna, Eisenstadt, and Leibnitz stand out for their very high exposure to numerous hot days with temperatures of 30°C and above last year. While the city center of Leibnitz has at least a moderate proportion of green space—around 36.8 percent—the situation is particularly critical in Wolfsberg: Here, the highest heat exposure (40 hot days) coincides with by far the lowest proportion of green space in the city center (17.5 percent). There is an urgent need for action in all six cities.

Greenpeace is using this as an opportunity to hold cities accountable: With the “NaturStadt Guarantee,” cities can make a binding commitment to their residents to increase the proportion of green spaces and effectively combat the urban heat island effect.

Home heat trap, risk of dangerous incidents with air conditioners increases

A Wealth Tax Could Strengthen Local Governments

Many German cities and municipalities lack the funds for shaded schoolyards, swimming pools, unpaved areas, and heat protection for older adults. Revenue from an ecologically designed wealth tax of 2 percent on assets exceeding 100 million euros could sustainably strengthen municipal finances, according to a new study by the Forum for Ecological-Social Market Economy (FÖS) commissioned by Greenpeace Germany. According to Greenpeace’s calculations, it could generate around 25 billion euros annually and affect fewer than 5,000 households.

 

Anyone who turns on the air conditioner is making the problem worse

While air conditioning systems cool indoor spaces in the short term, they do not solve the problem of urban overheating. On the contrary, they generate additional heat that radiates into the surrounding environment, further exacerbating the heat stress in public spaces. In the long term, we need sustainable alternatives that naturally buffer heat—so-called nature-based solutions.

District cooling - the climate-friendly alternative to air conditioning

Systemically Important Green Infrastructure

Plants cool cities in several ways: They provide shade for surfaces, reduce direct sunlight, and thereby slow the heating of building facades, roofs, and streets. At the same time, they provide cooling through evaporation.

“This turns trees, flower beds, green spaces, and green roofs into natural air-conditioning systems and thus into indispensable, systemically important infrastructure in cities plagued by climate change. Greening our cities is not optional—it is a must.”

Stephanie Drlik, Executive Director of the Austrian Society for Landscape Architecture

Urban greening is no longer just for decoration—it’s becoming the air conditioning of the future

The midsummer temperatures are once again taking a toll on many workers. People who work outdoors, in particular, are suffering from the heat. But even in non-air-conditioned indoor spaces, the summer workday becomes an agonizing challenge. This affects not only the employees themselves but also their performance and ability to concentrate. But at what temperatures do certain measures apply? As an employee, can I take time off due to the heat? We’ll explain the regulations in Germany and Austria!

 

Heat in the Workplace: A Strain on the Body and Concentration

The human body needs energy to maintain a constant core temperature. When outside temperatures are high, this energy demand increases further. The body tries to release excess heat through blood flow to the skin and sweating. This process requires fluids, and an insufficient supply can lead to increased physical strain.

In an office setting, the effects are often less obvious than with physical work outdoors. Typical consequences may include:

decreased concentration and attention
faster onset of fatigue
decreased motivation
headaches or feeling unwell
increased likelihood of making mistakes

Activities that require sustained mental focus, in particular, can be impaired by heat.

 

Germany: Protection Against Heat-Related Hazards

In Germany, there is no legal right to time off due to heat. However, under the Occupational Safety and Health Act and the Workplace Ordinance, employers are required to protect employees from health hazards caused by heat. These obligations are specified in ASR A3.5, “Room Temperature.”

The 3 temperature settings

At room temperatures of 26 °C or higher

 

The temperature should not be exceeded if possible. If this cannot be avoided due to high outdoor temperatures, the employer should take initial measures, such as:

Sun protection (blinds, roller shutters)
Ventilating in the early morning or at night
Fans
Relaxing the dress code
Providing drinking water

When the room temperature reaches 30 °C or higher
At this point, the employer must take effective measures to reduce heat stress. Possible measures include:

Schedule work hours for cooler times of the day
Provide additional rest breaks
Use fans or air conditioners
Consistently use sun protection
Provide cool beverages
Reduce internal heat sources

 

At room temperatures of 35 °C or higher

A workspace is generally no longer considered suitable. Work may only take place there if special protective measures are in place, such as:

Air showers or mechanical cooling
Special heat-protective clothing
Cool-down periods or frequent breaks in cool rooms.

 

Will school be canceled due to the heat?

No. Even at 35 °C or higher, there is no automatic right to go home or stop working. However, the employer must take appropriate protective measures. Only if there is a significant health risk and the employer takes no action despite being notified may further legal steps under labor law be considered.

 

Employees with Special Protection

Stricter occupational safety requirements apply to certain groups of people, including:

Pregnant women
breastfeeding mothers
employees with pre-existing health conditions
older employees

In such cases, the employer may be required to take additional individual protective measures.

In a nutshell

Up to 26 °C – should not be exceeded if possible
Above 26 °C – initial protective measures should be taken
Above 30 °C – the employer must take effective measures
Above 35 °C – the workspace is generally unsuitable, unless special protective measures are in place

These regulations apply to indoor workplaces such as offices, workshops, or production facilities. For outdoor work (e.g., construction, agriculture, or road construction), additional guidelines and risk assessments apply.

Austria: Stricter Heat Protection Regulations in Effect Since the Start of the Year

In Austria, new and stricter rules have been in effect since January 1, 2026. Nevertheless, the same applies here as well:

There is no legal right to time off due to heat. Employees may not simply leave their workplace because of the heat. However, employers are required to protect the health of their employees.

The new Heat Protection Regulation of 2026 is considered a milestone in Austrian worker protection, as it mandates binding protective measures for outdoor work for the first time. For indoor workplaces, however, the Chamber of Labor continues to call for stricter legal requirements.

Indoor work (office, workshop, production)

The provisions of the Workplace Ordinance (AStV) apply to workspaces:
• For light physical work, the air temperature should not exceed 25 °C.
• For normal physical work, the upper limit is 24 °C.

If these temperatures cannot be maintained due to weather conditions, the employer must take appropriate measures, such as:

Sun protection
Ventilation
Fans or cooling systems
Organizational measures such as adjusted work schedules or additional breaks

However, there is no fixed temperature (e.g., 30 or 35 °C) above which work is automatically prohibited, as is regulated in Germany by the ASR. Instead, the employer’s risk assessment determines the policy.

 

Working Outdoors

A lot has changed here since 2026:

As soon as GeoSphere Austria issues a Level 2 heat warning (30–34 °C), employers must implement a heat protection plan. This includes, for example:

Provision of drinking water
Shading of workstations
Shifting work hours to cooler times of day
More frequent rest breaks
Reduction of physically demanding work
Protection from UV radiation

Special Provisions for the Construction Industry

The following also applies to construction workers:
When the temperature exceeds 32.5 °C, outdoor work may be suspended if no suitable, cooler workplace is available. This is based on the Construction Workers’ Bad Weather Compensation Act. The decision is made by the employer.

In a nutshell

Time Off Due to Heat: There is no legal entitlement
Indoor Workplaces: Employers must take appropriate measures against heat
Outdoor Work: Starting in 2026, a heat protection plan will be mandatory once a GeoSphere heat warning reaches Level 2 (30–34 °C)
Construction Workers: Option to suspend work when temperatures exceed 32.5 °C under certain conditions

Our pro.earth.conclusion:

Due to the sharp increase in the number of hot days and tropical nights, we must focus intensively—especially in urban centers—on how to make buildings, production facilities, and schools more heat-resistant, and on what accompanying measures we can take to protect our health so that we can continue to work effectively even in extremely high temperatures. Because one thing is clear: heat waves will continue to increase in the coming years due to the climate crisis.

If you believe TikTok, tan lines and excessive sunbathing are all the rage. Yes, we need sunlight to produce vitamin D—about one-third of the population is deficient in vitamin D—but too much of it can be very harmful. Excessive UV radiation causes sunburn, makes our skin age prematurely, and, in the worst case, can lead to skin cancer. Skin cancer rates have risen sharply over the past 30 years. Sunscreen products offer a solution, but some contain problematic ingredients. We’ll explain.

 

According to the Federal Office for Radiation Protection, the incidence (the number of new cases per 100,000 people per year) of non-melanoma skin cancer has increased fivefold among women and fourfold among men over the past 30 years. Today, approximately 300,000 people are newly diagnosed with skin cancer each year, and 4,000 die from it. This represents a significant increase over the past 20 years, according to the Federal Statistical Office.

“With regard to the rise in temperature caused by climate change, scientific models have shown that a global increase in ambient temperature of 2 °C and the associated climate changes—which can lead to extreme heat and heat waves in certain regions—could increase the incidence of skin cancer by 11 percent by 2050,” explains the Federal Office for Radiation Protection.

 

That is why it is crucial to protect our skin from excessive UV radiation, especially during periods of extreme heat and intense sunlight, such as we are experiencing right now. We can do this by wearing appropriate clothing and head coverings, as well as by using sunscreen products.

 

Chemical vs. Mineral (Organic) Sunscreens

Chemical UV filters enter the bloodstream

We strongly advocate organic sunscreen. Why? Conventional sunscreen contains chemical UV substances that can be harmful to health. Some can trigger allergies, others behave like hormones in the body. This happens because these filter substances penetrate the skin barrier and enter the human bloodstream. UV filters have been detected in human blood and even in breast milk in excessively high doses. There is also a suspected link between reduced fertility and the chemical UV filters. The impairment of the function of human sperm was proven in a Danish study.

In February 2026, the Federal Environment Agency (UBA) published the results of a study of urine samples from children and adolescents. The study found that 92 percent of all samples contained a breakdown product of the hazardous plasticizer di-n-hexyl phthalate (DnHexP), which is banned in the EU due to its reproductive toxicity. The source of this contamination is UV filters—so-called DHHB filters—in sunscreens.

As early as 2024, the Federal Environment Agency detected mono-n-hexyl phthalate (MnHexP) in the urine of adults. MnHexP is a breakdown product of the plasticizer di-n-hexyl phthalate (DnHexP), which is considered harmful to reproductive health and is suspected of causing infertility. The findings were traced to contamination of a UV filter in sunscreens.

The EU has introduced new limits for DnHexP in cosmetic products, and starting in 2027, stricter EU-wide limits will apply to sunscreen and other cosmetics; after a transition period, violations of these limits may be subject to penalties.

Expired products should also no longer be used, because the breakdown of chemical compounds can result in substances that are potentially harmful to health, especially if the products contain certain ingredients such as parabens, PEG compounds, benzophenone-3 (oxybenzone), or octocrylene.

… and into the sea

The American Maritime Administration estimates that 14,000 tons of sunscreen end up in the sea worldwide every year and remain there because the chemical UV filters are poorly soluble in water. Some sunscreen products contain octocrylene, oxybenzone (sometimes also declared as benzophenone-3 on the list of ingredients) and/or octinoxate - chemicals that researchers believe are partly responsible for coral death. As a result, certain chemical substances have been banned in some countries (such as Thailand and Haiwai).

Studies in scientific circles are also discussing whether it could also be harmful to us humans. They are suspected of being potentially carcinogenic and endocrine disruptors, but long-term studies on their effectiveness are lacking.

The "Coral Reef Friendly" label means that companies have committed to omitting those ingredients in their production that have a negative effect on the underwater world.

 

Organic sun creams use mineral UV filters

These work like mini mirrors and reflect the sunlight on the skin. Mineral UV filters with titanium oxide and zinc oxide form a protective layer on the skin and do not penetrate the skin barrier. The disadvantage is "whitening", i.e. a white layer on the skin. To counteract this, the mineral particles have become smaller and smaller in recent years, sometimes in nano-size. It has not yet been fully clarified whether these nanoparticles can penetrate the skin barrier.

 

You should therefore opt for environmentally friendly, nanoparticle-free sun protection products, which unfortunately are not available everywhere.

As Europe suffers through its second heat wave of the year, it’s becoming clear that cities, in particular, are heating up significantly. Asphalt, concrete, and impervious surfaces store heat and release it again at night. This creates so-called heat islands, where temperatures can be several degrees higher than in the surrounding areas. As a result, more and more cities are turning to urban greening. Trees, parks, green facades, and green roofs are intended not only to beautify the cityscape and enhance well-being, but also to become a key part of the infrastructure in the fight against the consequences of climate change.

Facts and Figures

Europe is the continent warming the fastest.
In densely built-up urban areas, temperatures during heat waves can be up to 10 °C higher than in the surrounding countryside.
Green spaces can lower the local ambient temperature by several degrees.
A mature deciduous tree can filter several kilograms of particulate matter per year and store several metric tons of CO₂ over its lifetime.
Green spaces with trees and shrubs thus become carbon sinks.
By 2050, approximately 80 percent of Europeans are expected to live in cities.

BOKU research project investigates heatwaves and countermeasures in urban areas

 

Why Do Cities Heat Up So Much More?

There are many reasons for this:

For example, surfaces sealed with concrete and asphalt absorb solar radiation and transfer the heat to deeper layers.
In addition, because there is less vegetation in cities, less water evaporates to cool the air.
Buildings also contribute to the heat island effect by increasing the city’s surface area—where heat is stored—and by reducing air circulation.
The many rooftops also contribute to cities heating up more.
Similarly, exhaust emissions from traffic and industry contribute to this effect.
Heating and cooling systems further intensify the heat.
Parked cars also generate more heat.

 

Trees cool more effectively than many technical solutions

Plants act like natural air conditioners. Through shade and evaporation, they can significantly lower the ambient temperature. Studies show that green spaces can be several degrees cooler on hot days than heavily paved areas.

Urban trees, in particular, play an important role in this regard. On a hot summer day, a mature tree can evaporate several hundred liters of water, thereby actively helping to cool the environment. At the same time, trees filter fine particulate matter from the air, sequester CO₂, and improve the quality of life in densely built-up areas.

Green roofs and facades are also becoming increasingly important. They reduce the amount of heat absorbed by buildings, store rainwater, and create additional habitat for insects and birds.

 

From a Concrete City to a Climate-Resilient City

Many European cities are already working on long-term adaptation strategies. In addition to creating new green spaces, they are removing pavement from streets, expanding parks, and implementing so-called “sponge city” concepts. The goal is to store rainwater locally while also taking advantage of the cooling effect of plants.

Especially in densely populated urban areas, the combination of green spaces, water management, and sustainable urban planning will be a decisive factor in quality of life in the coming decades.

Experts believe that investments in urban green spaces will become just as important in the future as investments in transportation, energy, or water supply. After all, adaptation to climate change begins where people live: in cities.

Europe's New Reality: How Sponge Cities Help Combat Water Scarcity

 

German Environmental Aid (DUH) Reveals Loss of One Million Trees in Cities

According to the DUH’s latest Heat Check, the opposite trend is taking place in Germany—the residents of the cities surveyed are finding themselves with less and less protection from the consequences of the climate crisis. According to a press release, more than 900,000 trees have disappeared from the 195 cities surveyed—all of which have populations of more than 50,000—between 2018 and 2025.

Only seven cities meet the scientifically recommended benchmark of at least 30 percent tree canopy cover—including Hamburg, Berlin, Oldenburg, Potsdam, and Solingen. Since new areas were paved in all the cities studied, the DUH was unable to award a single “green card” for the paving trend. In terms of the heat vulnerability index—which is composed of the indicators of land sealing, green space volume, surface temperature, and population density—the situation has actually worsened compared to the previous year: Although a total of five more cities were examined than in 2025, the number of green cards has dropped from 28 to 21.

In the overall rankings, the cities of Offenburg, Lahr, and Mannheim fare particularly poorly. Kiel and Wuppertal stand out positively.

Under the slogan “Trees Save Lives,” the DUH is launching a petition to preserve shade-providing trees at www.mitmachen.duh.de/stadtgruen. The DUH is also calling on citizens across Germany to report trees at risk of being cut down and to follow the example of Berlin’s “Baumentscheid” (Tree Decree) by taking action to bring more greenery to their cities.

 

Our pro.earth.conclusion:

Urban greening must be viewed as part of critical infrastructure. What appears today as a park, a row of trees, or a green facade could be crucial tomorrow in determining how well cities cope with the consequences of climate change. A key task is to drastically reduce the current rate of soil sealing, to reopen sealed surfaces to allow rainwater to infiltrate, and to preserve and replant natural sources of shade and cooling. For the benefit of us all.

Even before the start of the 2026 astronomical summer, Europe is already experiencing its second exceptional heat wave of the year. At the end of May, temperature records were broken in several countries, and by mid-June, temperatures had once again climbed to over 40 degrees Celsius. Meteorologists are calling it an unusually early and intense heat season.

But the consequences are no longer limited to health and agriculture. Roads, rail lines, power grids, data centers, and cities are coming under increasing pressure. The question is no longer whether Europe must adapt to more frequent heat waves—but how quickly it can do so.

 

The heat is putting Europe's infrastructure to the test

Europe is warming faster than any other continent. The exceptional heat in May 2026 demonstrated just how much climate patterns have already changed. France recorded its warmest spring since weather records began. The average temperature from March through May was 13.8 degrees Celsius, 1.7 degrees above the long-term average.

By the end of May, temperatures in parts of Europe were already 10 to 15 degrees above the usual levels for this time of year. In the United Kingdom, a temperature of 34.8 degrees Celsius was recorded—the highest ever measured in May.

Such extreme temperatures pose problems for infrastructure. Asphalt can deform, and rails expand, increasing the risk of track buckling. At the same time, electricity demand rises due to cooling and air conditioning, while high temperatures impair the performance of power grids and technical systems.

 

Cities Are Becoming Heat Hotspots

Urban areas are particularly affected. Concrete, glass, and asphalt store heat and release it only slowly at night. This creates what are known as urban heat islands.

During a heat wave, densely built-up urban areas can remain up to 10 degrees warmer at night than the surrounding countryside. The consequences range from higher energy consumption and poorer sleep to health risks for older adults and children.

Many cities are now responding with adaptation measures:

Greening of roofs and facades
Additional trees and green spaces
Removal of impervious surfaces
Water features for cooling
Shaded recreational areas in public spaces

These measures not only improve the urban climate but also reduce the energy needed for cooling.

Climate adaptation is becoming an economic necessity

The costs of extreme weather events have been rising for years. Damage to roads, railways, power grids, and buildings costs billions across Europe every year.

That is why more and more countries are investing in heat-resistant infrastructure. New road surfaces, more heat-resistant rails, digital sensor systems, and so-called "sponge city" concepts are intended to help mitigate the effects of extreme heat.

Experts largely agree: Even if global emissions were to decline rapidly, heat waves will occur more frequently in the coming decades. Climate adaptation will therefore become just as important a task as climate protection itself.

 

Facts and Figures

In 2026, France experienced its warmest spring since records began. The average temperature was 13.8 °C, about 1.7 °C above the long-term average.
In May 2026, temperatures in parts of Europe were at times 10 to 15 °C above average.
At the end of May, the United Kingdom recorded 34.8 °C, the highest May temperature ever measured.
In Portugal, a new national May heat record of 40.3 °C was set at the end of May.
Copernicus described the heat wave at the end of May as “exceptionally early and intense,” with regional temperature deviations of more than 10 °C above average.
In mid-June 2026, temperatures between 34 and 40 °C—and locally even above 40 °C—were again expected in France, even before the official start of summer.
For Vienna, maximum temperatures of 30 to 31 °C were already expected in June 2026.
Austria has warmed by about 3.1 °C since 1900, which is significantly more than the global average.

 

The current heat waves show that Europe faces more than just the challenge of climate protection. Increasingly, the focus is shifting to the question of how cities, transportation systems, and energy supplies can be adapted to a climate that is already significantly hotter today than it was just a few decades ago.