In the Netherlands, one municipality is spraying salted water on its roads to stop them from melting or cracking in the extreme heat. The salt extracts moisture from the air, which in turn cools the asphalt. Much of Germany's autobahn network has asphalt coated with a special substance that absorbs moisture more quickly, according to local authorities.

Austria's railway network has deployed an army of workers to paint a 5-kilometer stretch of rail track white. It wants to test whether the paint will help the steel tracks, which can expand and buckle during a heatwave, to stay cooler. The metal can rise to 70 degrees Celcius. Rail travelers near Blundenz, about 60 kilometers south of Lindau on Lake Constance shouldn't notice any difference.

Businesses face potential revenue losses if consumers sit out the sticky weather at home. Germany's Bayreuth Festival saw a wave of returned tickets for performances of composer Richard Wagner's operas due to a lack of air conditioning in the theater. The Berlin Dungeon, on the other hand, helped tourists to stay cool by filling coffins with icy water and inviting visitors to dunk their heads.

Europe's nuclear power stations rely on water from nearby rivers or seas to cool reactors used for electricity generation. A power plant at Grohnde, in central Germany, was due to be shut down on Friday afternoon because the water in the nearby Weser river was thought to be too hot. Lower Saxony's environment ministry said the plant would remain closed until the river temperature has fallen.

In the German city of Wuppertal, a water cannon truck has been put to what environmental activists would say is a much better use. Some 40,000 liters of water was sprayed on the side of roads to keep the much-loved trees alive, which city officials said also aids road safety. After all, falling dead trees are a danger to traffic. City workers have also distributed 400 water sacks to younger trees.

The heatwave has prompted a continent not known for air conditioning to consider, in unison, installing the temperature cooling devices. According to Google Trends, searches for air conditioning (Klimagerät in German, or climatisation in French) and similar terms have skyrocketed over the past week, along with "pubs with air conditioning near me" in Britain, which spiked 2,100%.

During exceedingly hot temperatures, European zoos have begun freezing their animals' food to help them stay cool. Fruit, vegetables and even fish have been turned into popsicles on which the animals can feast. In the southwestern German state of Baden-Württemberg, the public has been asked to watch out for grazing horses, cattle and sheep left without sufficient water and shade.

More than two-thirds of people will live in urban areas by 2050, according to the United Nations — but only some will live in cities where they can also enjoy nature. With just 2.2% of its land dedicated to public parks and gardens as of 2015, the Turkish city of Istanbul is one of the least green cities in the world. The government has proposed turning old public spaces into parks.

Figures collated by the World Cities Culture Forum show stark differences in urban planning in cities around the world. In Shenzhen, China, green space accounts for 40% of the cityscape, despite a booming construction sector that has dotted the city with skyscrapers. The crowded capital, Beijing, also says it's working to increase its urban green space, which is currently at more than 45%.

Parks encourage people to exercise. Spending time among the sights and sounds of nature is also linked to better overall mental health. It relieves stress and improves well-being, as well as promoting social interaction. Despite its reputation as a concrete metropolis, about a quarter of New York City is green, with more urban gardens popping up on former industrial sites for residents to enjoy.

Trees and plants also clean the air, so green spaces effectively make it safer to breathe. This is especially important in crowded cities like Tokyo, which according to a 2015 Bureau of Urban Development survey has just 7.5% green space. With a population of 9.2 million, many of whom are elderly, Tokyo's citizens are vulnerable to air pollution.

Concrete heats up cities and makes citizens more vulnerable to heat waves. This is called the urban heat island effect, meaning cities are typically much warmer than the surrounding land. But green spaces are a solution to this problem, as they help cool urban areas. Although public parks account for 35% of space in Los Angeles, the dense city is very familiar with the urban heat phenomenon.

Green spaces also absorb water to help prevent the kind of flooding seen in 2018 in Paris, some 9.5% of which is made up of green space. Engineered green spaces can even capture and purify stormwater runoff while protecting residential areas, making them a critical part of a city's flood management system. Paris is working toward planting 20,000 new trees by 2020.

Most emerging megacities, defined as having a population of more than 10 million, are in the global south. Bogota, Colombia, is a booming metropolis that dedicates 4.9% of its land to green spaces. As cities grow bigger and richer, they need to balance short-term economic development with the long-term health of citizens and the impacts of climate change.