# Japan heatwave persists – record streak, cooling surge

> Live situation record from CLSTR: https://clstr.news/situations/japan-heat-and-rainyseason-health-risks
> Updated: 2026-08-07T02:20:29.000Z. Sources: 206. Developments: 55.

The 2026 Japanese summer heatwave has intensified. From 13–19 July, a five‑day stretch of 40 °C‑plus temperatures – the longest since records began – was recorded in 37 prefectures, prompting the JMA to label the days “kokushobi” and declare a disaster. Hospital transports for heat‑related illness more than doubled to 10,857, with 14 deaths and 321 severe cases reported in a single week.

Health authorities have broadened heat‑stroke alerts to cover most of the country and issued Level‑2 warnings in Yamagata, Fukushima and Kumamoto, where wet‑bulb globe temperatures approached dangerous levels. Community measures continue, including heat‑stroke prevention ambassadors, school seminars and police‑run water‑safety campaigns.

Consumer demand for cooling solutions has surged. Retailers report brisk sales of portable air‑conditioners and a wave of low‑tech items such as frozen tenugui towels. New high‑tech and wearable products have entered the market: handheld and mist‑plus fans from Dyson, Sony and Shark; cooling scarves, aromatherapy towels, UV‑blocking umbrellas; Vibram “BREEZANDAL” shoes; cold‑gel primers and chilled facial sprays. Premium personal‑climate devices have also appeared, notably a designer “human refrigerator” priced at several thousand euros.

The Do Hiemon Box personal cooling cabin, marketed as a “human refrigerator,” has sold roughly 200 units to steel mills, construction sites, universities, evacuation shelters and leisure venues, offering rapid 15 °C interior cooling.

Amnesty International has warned that the disaster‑level heatwave constitutes a human‑rights crisis linked to climate inaction. Simultaneously, a “triple‑typhoon” system (Typhoons 13‑15) threatens additional heat‑related risks across central and eastern Japan.

Overall, escalating health alerts, expanded community programmes and a booming market for both low‑ and high‑tech cooling devices illustrate Japan’s mounting challenge in coping with an unprecedented summer heatwave.

## Claims

- Six central cities, chiefly in Aichi and Gifu prefectures, recorded temperatures above 40 °C, qualifying as “kokushobi”. (corroborated by 13 sources)
- Scientists attribute the heatwave’s intensity to human‑driven climate change. (corroborated by 13 sources)
- Japan recorded five consecutive days with temperatures exceeding 40 °C on 25 July 2026, the longest streak since records began in 2010. (corroborated by 12 sources)
- Tokyo hospitalised a record 453 people for heat‑related conditions, the highest daily total in 16 years. (corroborated by 11 sources)
- Nearly 11 000 people required emergency medical treatment for heat‑related illnesses between 13–19 July, with 14 deaths. (corroborated by 11 sources)
- Authorities declared the heatwave a “disaster” and urged the public to treat extreme heat as such. (corroborated by 11 sources)
- Japan records about 1 300 heat‑related deaths each year and aims to halve that number by 2030. (corroborated by 10 sources)
- Japan recorded a peak temperature of 41.8 °C in Isesaki on 5 August 2025, the highest temperature on record. (corroborated by 5 sources)

## Timeline

### 2026-08-07: Toyama Prefecture faces dangerous heat wave with temperatures over 35°C

Toyama Prefecture sees a heat wave with temps above 35 °C, prompting heat‑stroke alerts and advice to stay hydrated and cool.

2 sources. https://clstr.news/cluster/toyama-prefecture-faces-dangerous-heat-wave-with-temperatures-over-35c

### 2026-08-06: Japan heat wave raises heatstroke alerts in Yamagata and Fukushima

Japan's Yamagata and Fukushima regions faced extreme heat in early August 2026, triggering heat‑stroke alerts and affecting a newly reopened beach.

2 sources. https://clstr.news/cluster/japan-heat-wave-raises-heatstroke-alerts-in-yamagata-and-fukushima

### 2026-08-05: Trusco Nakayama's Do Hiemon Box cooling booths sold across Japan

Trusco Nakayama’s ¥1.5 million Do Hiemon Box cooling booths, sold to about 200 sites, aim to prevent heatstroke in Japan’s soaring summer heat and have been sent to Kumamoto shelters.

4 sources. https://clstr.news/cluster/trusco-nakayamas-do-hiemon-box-cooling-booths-sold-across-japan

### 2026-08-03: Japan faces disaster-level heatwave, surge in heatstroke deaths

Japan's 2026 summer heatwave broke temperature records, causing a surge in heatstroke emergencies and deaths, especially among the elderly, while Amnesty International warned the crisis reflects a global human‑

2 sources. https://clstr.news/cluster/japan-faces-disaster-level-heatwave-surge-in-heatstroke-deaths

### 2026-08-03: Japan faces heat wave and triple‑typhoon threat

Japan endures a heat wave with record highs and a triple‑typhoon threat as Typhoons 13, 14 and 15 develop, prompting heat‑stroke alerts and coastal warnings.

2 sources. https://clstr.news/cluster/japan-faces-heat-wave-and-tripletyphoon-threat

### 2026-07-31: Japan's heatwave strains health services and infrastructure

Japan's extreme summer heat, reaching 38‑40 °C, strains health services, power supplies and prompts warnings, while studies show metabolism drops in heat and ice eating offers no protection.

5 sources. https://clstr.news/cluster/japans-record-summer-heat-triggers-health-warnings-and-debunks-weightloss-myths

### 2026-07-31: Japan adds heat‑wave mitigation via umbrella sharing and cooling vans

Japan expands heat‑wave safety with Osaka’s Ikaasa umbrella‑sharing stations and air‑conditioned camping‑car rentals for outdoor work sites, responding to new extreme‑heat day designations.

3 sources. https://clstr.news/cluster/japan-adds-heatwave-mitigation-via-umbrella-sharing-and-cooling-vans

### 2026-07-31: Kagoshima, Japan Endures Record Temperatures as Typhoon Approaches

Kagoshima hit record 38 °C heat, prompting heatstroke warnings, with Typhoon 13 expected to affect the region from August 4.

2 sources. https://clstr.news/cluster/kagoshima-japan-endures-record-temperatures-as-typhoon-approaches

### 2026-07-30: Japan's Do Hiemon Box Human Refrigerator Unveiled for Heat‑Stricken Workers

Japan promotes traditional cooling tricks and launches the Do Hiemon Box, a €8,000 walk‑in cabin that keeps outdoor workers at 15 °C, targeting construction sites and similar settings.

2 sources. https://clstr.news/cluster/japans-do-hiemon-box-human-refrigerator-unveiled-for-heatstricken-workers

### 2026-07-30: Japanese retailers launch fan‑integrated clothing for hot summer

Japanese retailers Aoyama Shōji and Workman introduced fan‑equipped clothing for business and everyday wear, offering lightweight, temperature‑control garments priced from ¥2,900 to ¥17,490 as heat waves push >

2 sources. https://clstr.news/cluster/japanese-retailers-launch-fanintegrated-clothing-for-hot-summer

### 2026-07-27: Japan rolls out Do Hiemon Box personal cooling cabins amid heat wave

Japan's SDRS unveiled the Do Hiemon Box, a portable cabin cooling workers during extreme 40 °C heat, selling over 150 units for €8,000 each as heat‑stroke cases rise.

8 sources. https://clstr.news/cluster/japan-rolls-out-do-hiemon-box-personal-cooling-cabins-amid-heat-wave

### 2026-07-27: Japan Unveils Expensive ‘Human Refrigerator’ to Beat Heatwaves

Japan introduced a costly “human refrigerator” device for personal cooling during heatwaves, priced at several thousand euros.

4 sources. https://clstr.news/cluster/japan-unveils-expensive-human-refrigerator-to-beat-heatwaves

### 2026-07-27: Japan's summer drives surge in cooling gadgets and accessories

Japanese retailers spotlight cooling gadgets—from Dyson fans and Shark mist fans to Vibram shoes and Matsukiyo cold‑gel items—many at discounted prices, to help consumers cope with the summer heat.

4 sources. https://clstr.news/cluster/japanese-retailers-highlight-cooling-gadgets-for-scorching-summer

### 2026-07-25: Japan endures record five‑day streak of 40°C‑plus temperatures

Japan endured a record five‑day heatwave with temperatures ≥40 °C, prompting disaster declarations, 14 deaths, over 10,000 heat‑related hospital trips and a spike in portable AC sales.

23 sources. https://clstr.news/cluster/japan-declares-heatwave-a-disaster-as-record-temperatures-drive-thousands-to-hospitals

### 2026-07-25: Japan's Do Hiemon Box personal cooling chamber marketed amid deadly heatwave

Japan's SDRS sells the Do Hiemon Box, an 8,000‑euro personal cooling chamber, to combat a July heatwave that has caused over 10,000 heat‑stroke cases, 14 deaths and mass evacuations.

4 sources. https://clstr.news/cluster/japans-sdrs-launches-do-hiemon-box-cooling-chamber-as-heatwave-worsens

### 2026-07-25: Japan's new air‑conditioned jacket and mist‑hand fan aim to beat the summer heat

Japan introduces a fan‑integrated jacket and a mist‑producing hand fan to provide cooler comfort during extreme summer temperatures.

5 sources. https://clstr.news/cluster/japans-new-airconditioned-jacket-and-misthand-fan-aim-to-beat-the-summer-heat

### 2026-07-22: Japan endures record‑breaking heatwave with consecutive “kokushobi” days

Japan’s heatwave set a record with five consecutive 40 °C+ “kokushobi” days, over 10 000 heatstroke admissions, 14 deaths and nationwide alerts.

24 sources. https://clstr.news/cluster/japans-record-heatwave-drives-hospital-admissions-to-10year-high

### 2026-07-22: Japanese 'Do Hiemon Box' cooling cabins launched as heat wave hits

Japan's SDRS and TRUSCO unveiled the Do Hiemon Box, a vending‑machine‑style cooling cabin costing ~1.5 million yen, to protect workers from extreme heat.

6 sources. https://clstr.news/cluster/japan-launches-vendingmachinestyle-personal-cooling-booth

### 2026-07-20: Japan endures first ‘kokushobi’ heatwave as temperatures exceed 40 °C, prompting alerts and deaths

Japan’s first “kokushobi” heatwave saw temperatures over 40 °C, heat‑stroke alerts in most prefectures, 14 deaths, thousands hospitalized, and impacts on Mount Fuji climbers and indoor health.

42 sources. https://clstr.news/cluster/japan-faces-near40c-heat-as-tokyo-issues-hightemperature-alerts

### 2026-07-20: Japan launches Do Hiemon Box, walk‑in human cooling booth

Japan's Do Hiemon Box is a walk‑in, 15 °C cooling booth that blasts 5 °C air at users, easing heat‑exhaustion symptoms within 5‑10 minutes; priced at ¥1.5 M and aimed at workers amid record summer heat.

14 sources. https://clstr.news/cluster/japan-launches-personal-cooling-box-to-combat-heatstroke

### 2026-07-20: Komatsu City heatstroke death of 80‑year‑old man amid three‑day alert

An 80‑year‑old man died of heatstroke in Komatsu, Ishikawa, during the third consecutive heat alert day, the prefecture's first heatstroke death this year.

3 sources. https://clstr.news/cluster/komatsu-city-heatstroke-death-of-80yearold-man-amid-threeday-alert

### 2026-07-19: Tokyo Heat‑Mitigation Expo Showcases Wearable Cooling Tech

Tokyo’s July 15‑17 2026 Heat‑Mitigation Expo showcased wearable coolers, ice‑slurry fridges and other tech to fight record summer heat, drawing crowds despite temperatures above 30 °C.

5 sources. https://clstr.news/cluster/tokyo-heatmitigation-expo-showcases-wearable-cooling-tech

### 2026-07-19: Japan warns of rising summer drowning deaths as police conduct water‑rescue drills

Japan’s Tokai region and Kanagawa police urge life‑jackets and conduct rescue drills as drowning deaths rise, with 742 fatalities reported in 2025.

2 sources. https://clstr.news/cluster/japan-warns-of-rising-summer-drowning-deaths-as-police-conduct-waterrescue-drills

### 2026-07-18: Japan faces extreme heatwave with temperatures up to 38 °C

Japan endures a heatwave as temperatures top 35 °C nationwide, reaching 38 °C in several prefectures, prompting heat‑stroke alerts and warnings about climate‑related sleep loss.

15 sources. https://clstr.news/cluster/japan-issues-heatstroke-alerts-as-temperatures-soar-in-hiroshima-and-tochigi

### 2026-07-17: Tokyo doctors recommend heat‑stroke adaptation methods amid soaring temperatures

Doctors in Tokyo urge heat‑adaptation habits—diet, light exercise, and 40 °C baths—to curb a surge in heatstroke cases amid record summer heat.

4 sources. https://clstr.news/cluster/tokyo-doctors-recommend-heatstroke-adaptation-methods-amid-soaring-temperatures

### 2026-07-16: Japan launches lightweight summer suits and wearable fan for heat relief

Japan introduces ultra‑light ZERO Like® suits and the waist‑mounted ZERA MAX 2.0 fan, offering personal cooling options for the summer heat.

2 sources. https://clstr.news/cluster/japan-launches-lightweight-summer-suits-and-wearable-fan-for-heat-relief

### 2026-07-15: Japan heatwave pushes Hokkaido to 35°C and Kyoto to 36°C

Japan faces a heatwave on July 16‑17, 2026 with Kyoto hitting 36 °C and Hokkaido reaching 35 °C; thunderstorms are forecast for eastern regions as health officials warn of heatstroke risk.

5 sources. https://clstr.news/cluster/japan-endures-extreme-heat-and-storm-warnings-as-temperatures-soar-to-37c

### 2026-07-14: Cooling Wearable Fans Gain Popularity with New Neck and T‑Shirt Designs

Portable cooling wearables, including $25‑$50 neck fans in Canada and a ¥2,999 fan‑integrated T‑shirt in Japan, offer hands‑free relief from summer heat.

2 sources. https://clstr.news/cluster/cooling-wearable-fans-gain-popularity-with-new-neck-and-tshirt-designs

### 2026-07-14: Japanese chilled tenugui offers a low‑tech solution for better sleep in extreme heat

Freezing a traditional Japanese tenugui cloth offers a cheap way to cool the body and improve sleep during heatwaves, while experts note rising summer heat also fuels seasonal mood and sleep disorders.

7 sources. https://clstr.news/cluster/japanese-chilled-tenugui-offers-a-lowtech-solution-for-better-sleep-in-extreme-heat

### 2026-07-14: Japan expands heatstroke prevention with ambassadors and USJ event

Japan promotes heatstroke prevention through community ambassadors in Miyagi and a Universal Studios Japan event teaching children cooling techniques.

2 sources. https://clstr.news/cluster/japan-expands-heatstroke-prevention-with-ambassadors-and-usj-event

### 2026-07-14: Japan heat wave kills 7, triggers hyperthermia alerts in 25 prefectures

Japan’s July heat wave caused seven deaths, 4,580 ambulance trips for heat‑related illness and hyperthermia alerts in 25 prefectures; Tokyo urged workers to adopt a short‑sleeve dress code under its “Cool Biz”

6 sources. https://clstr.news/cluster/japan-heat-wave-kills-7-hospitals-treat-thousands-as-alerts-span-25-regions

### 2026-07-11: Japan issues nationwide heatstroke alerts amid soaring summer temperatures

Japan’s heatwave pushes temperatures to 36‑37 °C, prompting nationwide heatstroke alerts, cooling shelters, stricter workplace safety measures, and highlights rising agricultural deaths.

12 sources. https://clstr.news/cluster/japan-records-july-heatwave-highs-in-kumamoto-and-fukuoka

### 2026-07-11: Japan's heatwave spurs surge in portable cooling gadgets

Japanese retailers tout affordable fans, cooling stoles, ice packs, insulated bottles and an evaporative cooler as heatwave temperatures rise.

4 sources. https://clstr.news/cluster/japanese-retailers-promote-cooling-gear-for-summer-heat

### 2026-07-11: Japanese retailers introduce summer comfort shoes and cooling spray

Japan’s &MEDICAL unveiled KAMOLEG2.0 room shoes for indoor walking, while MUJI introduced a ¥990 cooling mist spray for clothes, both aimed at summer comfort.

2 sources. https://clstr.news/cluster/japanese-retailers-introduce-summer-comfort-shoes-and-cooling-spray

### 2026-07-10: Champion Black Edition pants and MUJI heat‑wave gear debut in Japan

Champion Black Edition launches cooling stretch pants, while MUJI rolls out five heat‑wave accessories—including a sweat‑absorbing inner, sunscreen sheet, cooling mist and clip fan—in Japan.

2 sources. https://clstr.news/cluster/champion-black-edition-pants-and-muji-heatwave-gear-debut-in-japan

### 2026-07-09: Japanese schools issue heatstroke alerts as national survey highlights rising cases

Japanese schools warn of heatstroke with hydration and break guidelines, while a Saraya survey shows doubled transports, 20% self‑reports, and delayed preventive actions nationwide.

3 sources. https://clstr.news/cluster/japanese-schools-issue-heatstroke-alerts-as-national-survey-highlights-rising-cases

### 2026-07-09: Japan's sports agencies boost safety with heat‑exercise guide and coaching seminar

Japan’s sports safety bodies promoted safe participation, hosting a coaching seminar and publishing heat‑exercise guidelines to prevent injuries and heat illness.

2 sources. https://clstr.news/cluster/japans-sports-agencies-boost-safety-with-heatexercise-guide-and-coaching-seminar

### 2026-07-09: Japan editors share top cool‑down products for the summer heat

Japanese editors recommend hand creams, cooling oils, insulated curtains, circulator lights, cold‑sensation bedding and other gadgets to stay comfortable during the country’s hot summer.

4 sources. https://clstr.news/cluster/japan-editors-unveil-top-cooling-products-for-the-heatwave

### 2026-07-08: Japan heatwave prompts cooling shelters and multiple heatstroke deaths

Japan’s heatwave spurs cooling shelters and triggers heatstroke alerts, with deaths reported in Nagasaki, Toyama, Akita and Tochigi as temperatures hit record highs.

7 sources. https://clstr.news/cluster/japan-issues-record-heat-alerts-cities-open-cooling-shelters-for-residents

### 2026-07-07: Japan's Yamagata and Fukushima regions face extreme heat warnings

Japan's Yamagata and Fukushima prefectures will see temperatures above 30 °C in early July, with heatstroke warnings issued as a strong Pacific high‑pressure system drives a severe heatwave.

3 sources. https://clstr.news/cluster/japans-yamagata-and-fukushima-regions-face-extreme-heat-warnings

### 2026-07-06: Japan records highest heatstroke death rate among 34 countries, study shows

Japan has the world’s highest heatstroke death rate at 5.8 per million, driven by elderly victims and many indoor deaths without air‑conditioning.

3 sources. https://clstr.news/cluster/japan-records-highest-heatstroke-death-rate-among-34-countries-study-shows

### 2026-07-06: Japan urges heatstroke prevention for outdoor leisure and workplaces as summer heat rises

Japanese surveys show 42 % face heat‑stroke risks during summer leisure, prompting calls for better hydration and pre‑activity checks; workplaces adopt new safety measures after a 2025 mandate.

3 sources. https://clstr.news/cluster/japan-urges-heatstroke-prevention-for-outdoor-leisure-and-workplaces-as-summer-heat-rises

### 2026-07-03: Japan hosts multiple community festivals and public events in July 2026

Japan holds a series of July 2026 community events, from student safety forums and international festivals to fireworks, station fairs and heat‑stroke walking initiatives.

14 sources. https://clstr.news/cluster/shiga-prefectures-aichi-river-gion-summer-festival-fireworks-scheduled-for-july-18

### 2026-07-03: Japan faces mixed rain and extreme heat as summer approaches

Japan's weekend forecast shows heavy rain in the west, clear skies and extreme heat in the east, with Hokkaido nearing 30 °C and Fukushima facing a sudden heat surge and upcoming heatwave.

2 sources. https://clstr.news/cluster/japan-faces-mixed-rain-and-extreme-heat-as-summer-approaches

### 2026-07-02: Japan school sports adopt heatstroke prevention measures amid extreme summer heat

Japanese school sports events, from middle‑school meets in Miyagi to high‑school baseball tournaments, are implementing heatstroke safeguards such as hydration protocols, health checks and morning‑evening game‑

2 sources. https://clstr.news/cluster/japan-school-sports-adopt-heatstroke-prevention-measures-amid-extreme-summer-heat

### 2026-07-01: Japan sees unusually cool June with record‑low heatwave days

June 2026 in Japan was unusually cool, with only four extreme‑heat days versus 490 a year earlier, prompting beach openings to be pleasant and heat‑dependent businesses to suffer; officials now forecast a hot,湿

2 sources. https://clstr.news/cluster/japan-sees-unusually-cool-june-with-recordlow-heatwave-days

### 2026-06-30: Sony and Torras Unveil Wearable Cooling Gadgets for Summer

Sony and Torras launched wearable cooling devices in the US, offering neck‑mounted temperature control for summer heat.

4 sources. https://clstr.news/cluster/sony-and-torras-unveil-wearable-cooling-gadgets-for-summer

### 2026-06-28: Japan and China use cooling ties and UV masks to beat summer heat

Japan adopts refrigerating ties, ice collars and damp towels, while China popularizes lightweight UV masks and facekinis, offering culturally specific ways to stay cool in summer heat.

2 sources. https://clstr.news/cluster/japan-and-china-use-cooling-ties-and-uv-masks-to-beat-summer-heat

### 2026-06-28: Japan and China adopt innovative cooling accessories to beat summer heat

Japan uses cooling ties, ice rings and damp towels, while China employs UV‑blocking face masks and facekinis, both reflecting cultural heat‑mitigation tactics.

2 sources. https://clstr.news/cluster/japan-and-china-adopt-innovative-cooling-accessories-to-beat-summer-heat

### 2026-06-28: Japan's retailers showcase new cooling apparel to beat summer heat

HDEX and KEYUCA roll out affordable cooling apparel and accessories in Japan to help consumers stay comfortable during the upcoming heat wave.

2 sources. https://clstr.news/cluster/japans-retailers-showcase-new-cooling-apparel-to-beat-summer-heat

### 2026-06-22: Japan expands heatstroke prevention in schools and retail spaces

Japan issues new school heat‑stroke guidelines, promotes external sun shades, and retailers add cooling shelters and heat‑prevention product packaging amid rising humidity‑related cases.

6 sources. https://clstr.news/cluster/japan-expands-heatstroke-prevention-in-schools-and-retail-spaces

### 2026-06-18: Japan sees sudden rainstorms, hail and heat as tropical low develops

Japan experienced sudden rain, hail, thunderstorms and true summer heat across multiple regions on June 19, while a tropical low south of the country raises weekend rain concerns.

4 sources. https://clstr.news/cluster/japan-sees-sudden-rainstorms-hail-and-heat-as-tropical-low-develops

### 2026-06-18: Japan doctors advise ice slurry, oral rehydration and salt candy to prevent heatstroke

Japanese doctors recommend ice slurry, ORS and salt candy—used with water—to combat dehydration from heatstroke during the summer.

2 sources. https://clstr.news/cluster/japan-doctors-advise-ice-slurry-oral-rehydration-and-salt-candy-to-prevent-heatstroke

### 2026-06-16: Japan's sweltering summer spurs personal coping stories and cooling‑gear reviews

Japanese summer heat drives personal wellness tips and a review of TORRAS’s COOLIFY neck cooler to combat rising temperatures and heatstroke risk.

2 sources. https://clstr.news/cluster/japans-sweltering-summer-spurs-personal-coping-stories-and-coolinggear-reviews

### 2026-05-29: Japan faces rising fatigue and heat risks as rainy season approaches

Survey shows over 70% of Japanese feel fatigue before the rainy season, while Typhoon No. 6 threatens heavy rain and heightened heat‑stroke risk as the season starts.

2 sources. https://clstr.news/cluster/japan-faces-rising-fatigue-and-heat-risks-as-rainy-season-approaches

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Cite as: Japan heatwave persists – record streak, cooling surge. CLSTR, https://clstr.news/situations/japan-heat-and-rainyseason-health-risks