Tokyo ramps up Cool Biz push as extreme heat grips the city

Tokyo is expanding its Cool Biz campaign with new heat-safety tools, public contests and cooling maps as the city braces for hotter summers and rising heatstroke risk. The effort mixes clothing changes, workplace flexibility and public guidance aimed at helping residents and workers stay safe.

Why it matters: - Tokyo is trying to reduce heatstroke risk while also cutting energy use during increasingly severe summer heat. - The campaign affects workplaces, public facilities and daily routines across a city of about 14 million people. - The initiative also reflects how climate adaptation is becoming a city-management issue, not just a personal comfort choice.

What happened: - Tokyo launched Tokyo Cool Biz in April as a city-specific push to encourage cooler clothing, living and working styles. - The metropolitan office began using the approach itself, with staff wearing shorts, T-shirts and sneakers where appropriate. - Tokyo’s Bureau of Environment then opened a photo campaign from June 26 to August 31 showing how residents, students and workers are using heat countermeasure goods in real life. - Tokyo also held an award contest in May for “heat countermeasure goods.” - Governor Yuriko Koike urged residents and workers to use heat countermeasure goods and to get through summer safely and comfortably.

The details: - The contest drew 113 entries. - About 29,000 citizens voted for winners from 12 finalists chosen by experts. - Four categories guided the contest: sunshade creation, water and salt supplies, body temperature management, and temperature measuring and monitoring. - Grand Prize winners included a smartphone app that finds shaded places and paths. - Another Grand Prize went to an evaporative cooling vest worn under an air-conditioned jacket. - Two additional Grand Prizes went to a kit with water bottles, cooling packs, face towels and OS-1 oral rehydration solution, and to a pyramid-shaped tabletop device that tracks room temperature and humidity and changes color from blue to red when conditions become dangerous. - Tokyo Cool Biz recommends T-shirts, shorts, fan-equipped clothing, short-sleeve tops and sneakers where appropriate. - The program also encourages satellite offices, telework, vacations and early morning work shifts. - For home and daily life, Tokyo lists heat stress checkers, rotating stockpiles of food and supplies, air-conditioners, sun umbrellas, insulated windows, energy-efficient homes and heat acclimatization. - Tokyo posted an online map in June showing public and private places where people can cool off and avoid heatstroke. - The map overlays multilingual guidance on the existing Tokyo WBGT Map. - WBGT stands for Wet Bulb Globe Temperature, a measure used to assess heat stress risk. - The cooling locations include “Cooling Shelters,” meaning air-conditioned indoor facilities, and “TOKYO Cool Share Spots,” which can be indoor or outdoor sites including natural parks and water recreation venues. - Tokyo’s official statistics show 28.7 million foreign visitors in 2025, an all-time high and 15.6% more than the previous year. - Tokyo recorded 29 days at 35C or higher across July, August and September last year, a record for the city. - Japan’s meteorological agency began using the term kokushobi, or severely hot days, in April for days that reach 40C or more. - Tokyo is using the “Futto-Kyo” slogan for a third straight year to raise public awareness of the heat. - The metropolitan government continues to promote traditional cooling practices such as uchimizu, or water sprinkling, and sensu or uchiwa fans. - Tokyo still urges residents not to hesitate to turn on air-conditioning when daytime temperatures exceed 27.1C. - The Bureau of Public Health said in June that the risk of heatstroke death is considered to increase above 27.1C, citing a joint study by the Tokyo Metropolitan Medical Examiner’s Office and the University of Tokyo Graduate School of Medicine. - In June, London Mayor Sadiq Khan praised Koike’s Cool Biz approach during a meeting at Tokyo city hall.

Between the lines: - Tokyo is widening Cool Biz from a dress-code message into a broader resilience strategy that includes work patterns, public infrastructure and health warnings. - The continued use of shorts in government offices suggests the campaign is normalizing looser workplace standards, even if formal settings still require formal attire. - The emphasis on cooling shelters and multilingual maps shows Tokyo is also targeting tourists and non-Japanese residents, not only local office workers. - Koike’s comments suggest the campaign is meant to shift behavior and expectations, not just fashion.

What's next: - Tokyo will keep promoting its photo campaign through August 31 to show real-world use of heat countermeasure goods. - The city is likely to continue public messaging around cooling behavior as long as extreme heat persists. - Cooling shelters, Cool Share Spots and WBGT-based alerts are positioned to remain part of Tokyo’s summer response toolkit.

The bottom line: - Tokyo is treating extreme heat as a citywide safety problem, and Cool Biz is now one of its main tools for adaptation.