This summer (2025) I traveled to Paris, Croatia, and Hong Kong.  There are stark differences in the attitudes towards the use of air conditioning (AC) which I just took for granted as a given and something that should be used when needed. 

The summer heat in Paris was suffocating.  We were there during the heat wave, which was aptly named the “heat dome” because there was no escape.  During the day, the sun felt like hot charcoals roasting our skin when we were not in the shade.  There was no respite indoors as the AC in public buildings are mandated not to exceed 79F (26C) and the portable AC in our hotel room was only slightly better than being in the shade. The evenings offered respite from the punishing sun, but the heat radiating from the pavement kept the temperatures over 90F and we would still be dripping sweat while eating dinner at 10pm. 

I admire the energy conservation efforts especially in our ever-warming world, but on the flip side there are very real health consequences in staying in unrelenting heat.  I felt lethargic and drained even though I was excited to be on vacation. As it turns out, humans feel uncomfortable because our bodies are always producing heat to function and run metabolic processes and we need a temperature difference to release that heat from our bodies in order to maintain a homeostatic temperature (heh, heh, I am incorporating science terminology I learned). It’s like a data center without a cooling system, if the heat can’t disperse, our bodies can’t function properly, and we end up with heat stroke or other heat related illnesses.

In contrast, AC is used extensively throughout Asia. Not only is it important for comfort but it is also critical for dehumidifying.  My grandparents, who live in Hong Kong, told me that if they go without running the AC for even a few days, mold starts growing onto the walls, their clothes in the closet get musty, and things begin to deteriorate. Air conditioning in Asia feels like the polar opposite of Europe. While Europeans tend to use it sparingly, in many parts of Asia, it’s on full blast—everywhere. I love that sensation of being instantly chilled, like stepping into a refrigerator after being roasted outdoors. Sometimes it’s so cold indoors that I’ve learned to carry a jacket with me, even in the peak of summer. Still, I love the mega malls, those expansive, air-conditioned worlds where I can escape the heat entirely.  One mall in Guangzhou took things to a whole new level. They created an immersive winter wonderland modeled after the famous ice castles in Harbin, China. Inside, there was an ice rink designed to feel like a frozen lake, where you can walk or ride ice bikes.  They also had snowy hills to go snow tubing and slides made entirely of ice blocks that you can slide down. There were even real penguins chilling in an aquarium.

It was surreal— melting outside, yet freezing cold within this faux wintry world. We had to wear snow suits just to stay warm, and the moment we stepped back outside, my glasses fogged up instantly from the temperature shock.

The extreme use of air conditioning in parts of Asia can feel both disconcerting and excessive at first glance. But when you factor in population density, per capita usage, and the energy required to cool spaces with constant temperature fluctuations—especially in hot, humid climates—the picture becomes more nuanced. Dehumidification alone plays a major role in maintaining indoor comfort and preventing damage to property.

There are likely practical and cultural reasons why indoor environments are kept so cold. Still, I believe the ideal lies somewhere between the minimal use seen in much of Europe and the full-blast approach common in Asia—one that prioritizes both comfort and sustainability.

Other Thoughts:

• I really appreciate living in the temperate Bay Area where we don’t have or need an AC unit at home.  It rarely gets too hot or too cold where it can be life threatening.
• Fans are surprisingly effective at keeping you cool. While electric handheld fans are everywhere across Asia, I still prefer the cheap hand fans I used in Paris. They’re lightweight, portable, and no batteries are required.  The worse thing about electric fans are when they overheat and emit that burnt-motor smell. Not sure how it stacks against the latest fan upgrade – the fan jacket. These have built-in fans that circulate air inside the jacket, puffing it up like a marshmallow. It’s bulky, but does a solid job of cooling you down.
•  Installing numerous air conditioning units across Paris would ruin the charm of the historic facades, imagine rows of clunky AC units hanging off those beautiful old buildings and getting a random drop of water on your head. I also wonder if the infrastructure could handle it.  I heard its electrical grid was old so increased and widespread use of AC could strain the city’s electrical grid.
• If everyone suddenly decided to blast AC all summer, could the grid keep up? It feels like one of those situations where practicality and preservation are constantly at odds.

Harbin Ice Festival

Guangzhou Zhengia Penguin Ice and Snow World

Early Morning Paris – beating the crowds and heat