Japan Heatwave Overwhelms Hospitals as Temperatures Top 41C

TOKYO_More than 450 people were taken to hospitals for heat-related illnesses in Tokyo on Wednesday, the highest daily total since records began in 2010, as an intense heatwave swept across Japan, prompting authorities to describe the conditions as a disaster and urge residents to take precautions.

The Tokyo Fire Department said 453 people required hospital treatment for heat-related conditions on Wednesday, while emergency callouts reached their highest level since at least 1963. Officials said the number of patients rose as temperatures climbed sharply over recent days, with noticeable increases on Tuesday and Wednesday.

Authorities appealed to the public to remain hydrated and use air conditioning wherever possible to reduce the risk of heatstroke. Emergency services said the sustained high temperatures were placing growing pressure on medical responders as the heatwave continued across much of the country.

In Tokyo prefecture, which is home to about 14 million people, one person has died during the current spell of extreme heat, according to the fire department. Four other people were reported to be in critical condition and another 18 were listed in serious condition after suffering heat-related illnesses.

The Fire and Disaster Management Agency said on Wednesday that at least 14 people had died nationwide over the previous week because of the extreme heat, while approximately 11,000 people sought emergency medical treatment. The agency described the situation as a “disaster,” saying the number of hospitalizations and deaths made the characterization appropriate.

Heatstroke alerts have been issued across almost the entire country of roughly 125 million people. The agency warned that temperatures have continued to rise since the middle of July and said severe heat is expected to persist nationwide.

Central Japan has been among the regions hardest hit. In Aichi prefecture, which includes the city of Nagoya, local officials said 116 people were taken to hospitals on Wednesday because of heat-related illnesses as exceptionally high temperatures persisted.

Meteorological observations on Thursday showed that at least six locations had already reached temperatures of 40 degrees Celsius or higher by early afternoon. Three additional locations recorded temperatures of 39.9 degrees Celsius.

The highest temperature was registered in Hamamatsu, in Shizuoka prefecture, where the mercury reached 41.1 degrees Celsius. Toyota City in neighboring Aichi prefecture recorded 40.8 degrees Celsius, while Kuwana in Mie prefecture reached 40.7 degrees Celsius.

Japan’s highest temperature on record remains 41.8 degrees Celsius, measured in Isesaki, north of Tokyo, on Aug. 5, 2025.

Japanese authorities have also introduced a new expression this year for temperatures exceeding 40 degrees Celsius. The term, “kokushobi,” translates roughly as “cruelly hot day” and is intended to raise public awareness of dangerous heat conditions, although it does not automatically trigger nationwide emergency measures.

Visitors to Tokyo described adjusting their daily routines to cope with the oppressive weather. American tourist Nick Estes said his family had planned activities around access to air-conditioned subway stations and shops, adding that the conditions felt even hotter than during a visit the previous summer.

Another visitor, Yesenia Gueta from Los Angeles, said the heat was already intense during the early morning and continued to build throughout the day. She said the weather had helped her understand why many people in Japan use umbrellas for shade and wear loose-fitting clothing during the summer.

Local residents also voiced concern about the prolonged spell of extreme temperatures. A 24-year-old university student identified as Nukochama said the heat in mid-July raised concerns about conditions later in the summer and said carrying a rechargeable portable fan had become part of daily life.

Scientists have consistently said that human-induced climate change is increasing both the frequency and intensity of extreme heat events in Japan and around the world. Japan experienced its hottest summer on record last year, and authorities continue to warn that prolonged exposure to high temperatures significantly increases the risk of heatstroke, particularly among older adults, children and people with underlying health conditions.