21 people, including a 4-year-old girl, were transported on suspicion of heatstroke in Tokyo ── A guide to "Tokyo's Summer" measures that confronts foreigners with midsummer-level heat

1. Today's Transport Situation and Preliminary Figures

On Monday, June 16, 2025, the Tokyo Fire Department announced that "a total of 21 people (aged 4 to 96) were transported by ambulance with symptoms suspected to be heatstroke between midnight and 3 p.m." Among those transported, 7 were moderately injured and 14 were lightly injured, and none are believed to be in life-threatening condition. However, the Tokyo Metropolitan Government continues to call for caution. The Fire Department commented, "Please use air conditioning if the perceived temperature is high indoors, and refrain from enduring the heat." newsdig.tbs.co.jpnews.ntv.co.jp

The rising temperatures are attributed to ① the temporary northward movement of the rainy season front expanding clear skies, ② the extension of the Pacific high-pressure system, and ③ the compounded effect of the urban heat island in central Tokyo. The observed temperature in central Tokyo (Otemachi) at 1 p.m. was 31.4°C with a humidity of 63%. The WBGT exceeded the caution level of 28, recommending that outdoor activities be "principally suspended or shortened." suibun-iinkai.jp

2. Why is Tokyo's Summer "Humid"? — Comparison with Major Cities Worldwide

• Latitude and Maritime Climate: Tokyo is located at 35 degrees north latitude, similar to New York and Rome, but its humid Pacific monsoon climate accentuates the humidity.
  
  

• Urban Heat Island: Asphalt and skyscrapers hinder nighttime heat dissipation, keeping minimum temperatures high.
  
  

• Westerlies and Rainy Season Front: During clear spells at the end of the rainy season, high humidity and high temperatures arrive simultaneously, causing the WBGT to rise sharply.
  
  

According to data from the Japan Meteorological Agency, Tokyo's average summer relative humidity is 71%. Compared to cities at the same latitude like Madrid (33%) and Los Angeles (66%), it is higher, raising the perceived temperature. When the WHO's "30°C and 60% humidity" threshold is exceeded, outdoor work requires mandatory breaks, but Tokyo's midsummer days easily surpass this standard. newsdig.tbs.co.jp

3. Challenges and Solutions Faced by Foreigners

3-1 Language Barriers and Medical Access

• Emergency Calls: In Japan, call 119 (Fire/Ambulance). The voice guidance is in Japanese, but the Tokyo Fire Department offers a three-party call service in English, Chinese, and Korean.

• Consultation Dial #7119: Available for use when unsure if symptoms are initial signs of heatstroke.

• Embassies in Japan: Often issue their own health alerts during the summer.
  
  3-2 Indoor and Outdoor Practical Self-Care

4. If Symptoms Appear ─ 5 Steps to Prevent Severe Conditions

1. Move to a Cool Place : Nearby convenience stores or public facilities with air conditioning are acceptable.

2. Loosen Clothing and Cool Neck, Armpits, and Groin : Wrapping and applying a bottled drink can be effective.

3. Oral Rehydration Solution or 0.1% Salt Water in Small Amounts : Do not give if vomiting or consciousness is impaired.

4. Call 119 Without Waiting for Recovery : Especially for children and the elderly.

5. Utilize Multilingual Support Apps : Such as the medical interpretation app "Pocket Doctor."
   
   

5. Heatwave Trends in Japan Due to Climate Change

The UN IPCC Sixth Assessment Report predicts that the frequency of extreme high temperatures in urban areas of Northeast Asia will double over the next 30 years. According to statistics from the Tokyo Metropolitan Government, the number of midsummer days has increased by an average of 16 days per year compared to the 1990s.

The record high temperatures are now occurring at a pace of "once every few years" instead of "once every few decades." In response to this, the Ministry of the Environment will introduce a special heatstroke alert from 2024. The app "Heatstroke Alert" (English version) is also recommended for foreign tourists.  newsdig.tbs.co.jp

6. Conclusion

• On June 16 alone, 21 people were transported. Tokyo's summer is a triple threat of "high temperature + high humidity + urbanization."

• Pay attention to WBGT and humidity, and plan outdoor activities with consideration of time and rest frequency.

• 7119 for mild cases, 119 for emergencies. Utilize multilingual interpretation and embassy information.

• The risk of extreme heat due to climate change is increasing year by year. Both travelers and residents should recognize that "heat is a health issue that transcends cultural barriers."
  
  

Reference Article List

• TBS NEWS DIG "21 People, Including a 4-Year-Old Girl, Transported on Suspicion of Heatstroke in Tokyo" June 16, 2025 newsdig.tbs.co.jp

• NTV NEWS "21 People Transported by Ambulance Due to Heatstroke in Tokyo Fire Department Jurisdiction" June 16, 2025 news.ntv.co.jp

• Tokyo Fire Department "Heatstroke Prevention Handbook (Revised Edition)"  tfd.metro.tokyo.lg.jp

• Ministry of the Environment "Heatstroke Special Alert Operation Guide" wbgt.env.go.jp

• WHO “Global Heat Health Information Network”   ghhin.org

• Japan Meteorological Agency "Tokyo WBGT List by Heart Temperature Conditions"  jma.go.jp