Tokyo wants you to wear shorts to work. Say no.

By Gearoid Reidy

JAPAN has long relied on innovation to beat the heat. From the invention of sensu fans that could be folded up into a kimono in the Heian era more than 1,200 years ago, to parasols which in recent years have found users among men as well as women, the country has learned to adapt.

But the capital’s government might have gone one innovation too far this year. As part of its “Tokyo Cool Biz” campaign to deal with increasingly sweltering summers, and with an eye to higher energy prices due to the war in Iran, it’s allowing government workers to wear shorts to the office for the first time — and encouraging companies to follow suit.

It’s part of a campaign that encourages men and women alike to dress down and prioritize comfort, including T-shirts, polo shirts, and short-sleeve tops. It has triggered a debate on how casual is too casual. A recent news segment went viral after vox-pop interviews featuring young women who overwhelmingly declared that having to look at middle-aged men’s legs at the office was “gross.”

While the image of the suit-and-tie salaryman endures, in recent years summer office fashions have become much more casual. The spark was an initial Cool Biz campaign in 2005 that was the brainchild of then-Environment Minister Yuriko Koike — now the governor of Tokyo. It gave permission to workers to abandon the jacket and necktie. Changing mores were supercharged during the COVID era as workers embraced comfort; these days, T-shirts and sneakers are part of the office wardrobe.

Summers were not as brutal in the 2000s as they are now, with the campaign aimed at saving energy, rather than lives. But for all the recent trend of hotter, longer summers, shorts take this permission structure too far. Shorts are fine at the park but, double standards be damned, they don’t belong at the workplace. And they almost inevitably lead to the wearing of sandals, arguably an even greater sin.

They’re also the wrong answer to what is a serious problem. Japan has been getting hotter, particularly in cities where higher temperatures are worsened by the urban heat island effect, when buildings and roads absorb sunlight only to release it after dark. The last few summers have been especially punishing, with a record 29 days last year in the capital above 35°C (95°F), known as moushobi, or “extreme heat day.”

That term is no longer sufficient to capture things: This year, the weather agency had to come up with a new term for when the mercury tops 40°C, now known as kokushobi or “severe heat day.” Tokyo has yet to see one of these, but it’s likely only a matter of time. Authorities have also begun issuing alerts for days when the risk of heat stroke is severe, based on the wet-bulb globe temperature that adds humidity and radiant heat to calculate how dangerous the environment is for the human body. Such deaths topped 2,000 nationally in 2024 for the first time.

In the Heian era, nobles used to flee to mountain retreats to beat the heat. Today’s challenges call for new solutions. The Tokyo government is also proposing lots of other practical changes, from early shifts to more remote work.

Most of all, the country is trying to free the public, particularly older generations, of old-fashioned views that encouraged people to grin and bear it. Authorities have largely abandoned the energy-conserving advice of the initial Cool Biz, which came with much-misunderstood guidance that encouraged a generation to set their air-conditioners to 28°C.* These days, they encourage the use of AC when the temperature soars — largely because of a disturbing increase in the number of elderly who have died in rooms where, despite being equipped with AC, the devices were never turned on.

In contrast to the scolding of some European countries that have prioritized conserving energy and the climate, Japan has gone on an air-conditioning spree. In the 1980s, less than half of households had the devices; now, thanks in part to subsidies, that’s well over 90%. In 2010, just 20% of public elementary and junior high classrooms had them; now it’s at 99.1%. It helps that the world’s biggest maker is Japan’s Daikin Industries Ltd.

Even with all the will in the world on climate — and there seems to be precious little of that these days — temperatures aren’t going to go down. Japan has been accused of dragging its heels on the energy transition despite facing very real domestic, geopolitical, and technological hurdles. As the world looks again at nuclear, that’s the solution closest at hand. Prime Minister Sanae Takaichi should redouble her efforts to boost atomic power, because Tokyo in August isn’t survivable through willpower alone.

For workers outdoors, there’s a different kind of uniform than shorts: Fan jackets, invented by a former Sony Group Corp. engineer in 2004. They’re equipped with multiple fans and batteries to cool the entire body, helping keep construction workers and road crews on their feet. Sony itself offers a luxury portable unit that cools the body by absorbing heat from the back of the neck.

And when it comes to the problem of uncovered legs, Japan has already found the solution, in the form of Uniqlo’s Kando Pants (known as AirSense in some markets) — breathable dress trousers that keep you cool, while also looking professional.

From sensu fans to cooling jackets, Japan has figured out how to survive summer over the centuries. Surely, then, it can also manage to do so with its trousers on.

BLOOMBERG OPINION

*Authorities insist they were telling people that the room temperature should be below 28°C, meaning the AC should be set lower.