Heatwave: What It Reveals about Our Cities.
- Joanne Yeung
- Jul 8
- 6 min read
Toronto, late June. I stepped outside around three in the afternoon to run an errand, and felt an invisible wall of heat stop me in my tracks. My phone flashed 35 °C, a grim badge for a city more accustomed to complaining about long winters. Even worse, I got the dreaded “iPhone needs to cool down before you can use it” warning, despite only holding it outdoors for a few minutes, doing nothing. We’re not alone: in Spain, parts of Andalusia were pushing past 46 °C. It felt eerie, almost cinematic, as if two distant worlds had merged under the same suffocating sky. But of course, this isn’t cinema. It is the shape of our summers now: stretching across continents, breaking records, and straining the systems we once assumed would always protect us.
For years, we framed climate change as a “future risk.” This summer is a stark reminder that it’s not future tense anymore. From Europe to North America to Asia, our cities are being stress-tested in real time. And for all our technological advances, it’s painfully clear that most are simply not ready.
A new meteorological baseline
This latest heatwave wasn’t just a fleeting encounter with hot weather. It was a multi-week siege, driven by a stubborn heat dome — a mass of high-pressure air trapping intense temperatures beneath it. Across Europe, this meant temperatures soared 8 to 14 °C above historical averages, smashing June and early July records from Portugal all the way up to southern Norway. Spain’s Andalusia region bore the brunt, with local highs creeping past 46 °C.
Perhaps even more worrying were the nights. In cities across Greece and Croatia, overnight lows barely dipped below 27 or 28 °C. This matters because the human body (and the power grid) relies on the cool of night to reset. Without it, stress accumulates, raising the risk of dehydration, cardiovascular failure, and respiratory distress. When the heat dome finally broke, the atmosphere released its pent-up energy in dramatic fashion: violent thunderstorms and hailstorms swept the Balkans, while tinder-dry forests across Greece, Spain, and Italy ignited in fresh wildfire outbreaks.
Across the Atlantic, North America faced its own parallel story. Much of the western United States and parts of Canada endured weeks of temperatures well above normal. While the east was more variable in June, new forecasts point to another ridge forming, setting up the next chapter in what is increasingly a season-long saga rather than an isolated event. Meanwhile, European climate data shows the region warming at roughly 2.2 °C above preindustrial levels — nearly twice the global average. Heatwaves are no longer exceptions. They are the new baseline.
The human toll: deaths that were not inevitable
The numbers emerging from this summer tell a sobering story. Early July’s heatwave alone has already claimed at least eight confirmed lives across Europe — four in Spain, two in France, two in Italy — with many more expected as excess mortality data is compiled. In Portugal, the final week of June saw 69 excess deaths, while Spain reported around 380 heat-related fatalities for the month. In the UK, researchers estimated approximately 570 additional heat-related deaths during just four days from June 19 to 22.
These figures are not flukes. They’re consistent with a rising trend across the continent. In the summer of 2022, roughly 61,700 Europeans died due to heat, with Mediterranean nations like Italy, Spain, and Greece shouldering the heaviest burden. As temperatures creep upward and extreme heat days become more frequent, we are on track to see these death tolls climb — unless cities and nations fundamentally rethink how they design, retrofit, and regulate urban life.
And of course, the health impacts extend far beyond mortality. Emergency rooms see spikes in dehydration, cardiac events, respiratory distress, and even mental health crises. Economically, productivity nosedives above about 33 °C wet-bulb globe temperature, hitting sectors from construction to logistics. Meanwhile, grids buckle under surging energy demand, driving up prices and raising the specter of rolling blackouts — as witnessed repeatedly across Southern Europe.
Are our cities ready?
If this summer has taught us anything, it is how unprepared many urban areas are for a climate that has already shifted. From housing to public health, policies was largely built for a climate that is rapidly slipping into history. One of the starkest divides lies in air conditioning penetration. In the United States, AC is nearly universal, with about 90% of homes equipped. In Europe, it’s an entirely different story: fewer than 10% of homes in France have air conditioning, and in the UK it’s under 5%. Even across the broader EU, penetration averages around 19%. Many older building stock means countless apartments were built for cooler and stable climate, with little thought of enduring weeks above 40 °C. (Growing up in Hong Kong, it’s almost unimaginable now to live without AC.)
Governments are scrambling to adapt. Greece made global headlines by closing the Acropolis to visitors during peak hours and banning most outdoor work between 10 am and 2 pm, enforcing heat curfews across southern regions. France issued multi-tiered heat alerts, closing over 200 schools and even restricting access to landmarks like the top deck of the Eiffel Tower. Italy, Spain, and Portugal activated regional heat-health surveillance systems, pushing out real-time public warnings. Germany, which has so far faced milder peaks, rolled out school operating guidelines that trigger at 40 °C.
Still, these are largely reactive measures. Resilience often depends on local politics or municipal budgets, meaning two neighbouring municipalities might face similar temperatures but provide vastly different protection. What happens if next summer’s heatwave is even hotter, or lasts a month longer? In too many cities, adaptation plans remain fragmented. Few cities have systematically invested in cool roof programs, expanded urban tree canopy targets, or mandated public cooling centers. Nighttime heat — often deadlier than daytime peaks — remains under-monitored or completely absent from local adaptation plans. True climate readiness will require coordinated national frameworks, deep infrastructure retrofits, and policies that prioritize the elderly, outdoor workers, and low-income residents - the groups that are least able to adapt on their own.
What does this mean for companies?
It would be a mistake to see this purely as a municipal or public health issue. For companies, these heatwaves represent a direct threat to continuity, costs, and long-term competitiveness. Worker productivity plummets once temperatures exceed critical thresholds, impacting construction, warehousing, agriculture, and delivery sectors. Heat also warps physical infrastructure, softening asphalt, buckling rail tracks, and threatening the integrity of cold-chain systems in food and pharma logistics. In fact, my commute to downtown Toronto was interrupted a few times due to issues related to railway track because of the extreme heat. In the energy sector, European grids saw wholesale prices more than double in some markets this summer as solar output surged but thermal plants struggled under water cooling constraints.
Leading firms are already responding by building climate contingencies into their operations. They’re shifting deliveries to cooler hours, investing in next-generation cold-chain technologies, diversifying warehouse hubs to avoid clustering risks, and integrating weather-triggered clauses into logistics contracts. Many are also exploring parametric insurance products that pay out automatically when temperature indices exceed agreed thresholds — helping stabilize cash flows and fund emergency adaptation. Some large retailers are partnering with municipalities to operate stores as pop-up cooling centers during red alerts, blending brand stewardship with practical risk reduction.
Looking ahead — and a personal note
Last night, it was 28 °C in my bedroom at midnight and I couldn’t sleep, even though I grew up in subtropical climate and had AC at home. It seems like AC can never move the temperature down further. With my sweating back, I lay awake thinking about how millions of people, from Toronto to Thessaloniki, now experience this as a normal summer night. How are we going to adapt to these tropical summers with our current infrastructure? Most public schools in Greater Toronto Area still lack air conditioning in classrooms. Even though schools have implemented various measures to help students cope, kids often bring their own mini fans, ice packs, and oversized water bottles. Suddenly, it feels like I’ve been transported back to my school days in Hong Kong over 30 years ago, when my classmates and I tried to concentrate in furnace-like classrooms under four fiercely spinning ceiling fans.
If there’s a fragile silver lining, it’s that these heatwaves act like audits, exposing the fault lines in our systems early enough that we still have a chance to adapt. Air conditioning alone isn’t the answer. We need systematic solutions: cities must retrofit buildings, expand tree cover, rethink street design, and ensure public health systems are prepared for days and nights that refuse to cool down. Companies need to treat climate risk not as a vague CSR talking point, but as a direct operational and supply chain imperative.
The next heatwave isn’t hypothetical. It’s already on the horizon.
[First published in Substack "Ginci Insights" on July 9, 2025: https://gincinno.substack.com/p/heatwave-what-it-reveals-about-our?r=2cxt8s]
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