For those that can afford it, the go-to recourse for most perspiring city dwellers is the air conditioner remote. But, given that air conditioners are themselves a source of carbon dioxide, they form part of a viscous cycle that has become unsustainable.

However, Gartland, who has written a book on heat islands, takes heart from the strategies available to mitigate their impact. She considers cool roofing – which utilise materials with higher solar reflectance and emittance – as the most effective means of tackling the problem.

“Cool roofing can be cost-effectively integrated into normal roof maintenance and brings many benefits in addition to reducing the heat island, such as energy savings, improved building comfort and increased roof longevity,” she says.

“Green roofs are also very popular since they add to the ecosystem and retain stormwater. That said, they can be pricey and not every building can support their weight.”

Gartland also advocates substituting traditional asphalt pavements – which facilitate urban islands – with either porous tarmac or lighter coloured paving that is able to stay cooler and last longer. However, the easiest and cheapest measure at the disposal of city councils is planting more trees, she says.

“Planting trees is the go-to measure, since trees bring shade, cooling, stormwater retention and wildlife habitat. However, planting a tree is relatively easy, but nurturing it to maturity takes care and effort. Faster-growing plants like vines, shrubs, and ground covers are also helpful.”

There are also plenty of examples of architects taking up the gauntlet to combat the heat island effect. Having recently been commissioned to redesign Pilsudski Square in Warsaw – the city’s largest quadrangle – Polish practice FAAB is constructing what it claims to be Europe’s largest bicycle park.

The thinking behind the park, explains creative director Maria Messina, is to create a vehicle-light urban ecosystem that addresses climate change and heat islands (in August, the capital city recorded its highest ever temperature of 37.2C).

“The project includes a two-storey cycle park, that will be equipped with a multi-level bicycle storage system using specialist self-service racks,” Messina wrote in a note. “It is planned to contain 15,000 bicycle spaces, with an opportunity to expand to 20,000, as well as 570 parking spaces for electric vehicles.”

Last year, Dutch firm UNStudio partnered with Monopol Color, a Swiss paint manufacturer, to develop a new white, reflective coating system. Named “The Coolest White”, the paint is based on fluoropolymer technology that reduces the absorption and emission of the sun’s rays down to 12% – in contrast to darker materials that soak up around 95% of rays before releasing them back into the atmosphere.

The system is well-suited to metal facades and aluminium and steel structures, which have come to dominate many an urban skyline in recent years.

Elsewhere, fellow Dutch practice Mecanoo has incorporated sky gardens – aimed specifically at mitigating urban heat islands – into its design of the Futian Civic Culture Center in Shenzhen. In May 2018, the city, which lies in the Guangdong province of south-east China, and borders Hong Kong, saw temperatures reach 35°C – the highest on record for nearly 20 years.

According to UN projections, 2.5 billion people will be living in cities by 2050 – accounting for roughly 68% of the world’s population.

This transition will predominantly take place in Africa and Asia, where few have the luxury of turning on the air conditioning or opening the window when their apartment gets too hot.

As warned by MIT, cities in these regions run the risk of becoming man-made ovens that will stretch the limits of human survival. Innovations in the field of heat island mitigation – whether they be roof gardens, white coatings or cool pavements – could prove to be vital.