Japan's Environment Ministry launched a special heat stroke alert system Wednesday as part of efforts to address the increasing number of deaths due to the summer heat in recent years.

When the alert is issued, municipalities will open designated facilities such as libraries and community centers to residents as "cooling shelters." The system will be in effect through Oct. 23 this year.

If unprecedented, widespread and dangerous heat is expected, the ministry will make an announcement at around 2 p.m. the day before and call for canceling or postponing sports and other events that cannot take sufficient measures to prevent heat strokes.

Photo taken in September 2023 shows part of Tottori city hall in western Japan that is open to residents as a cooling shelter. (Photo courtesy of Tottori municipal government) (Kyodo)

A special alert will be issued for each prefecture. Specifically, the ministry looks at whether the "heat stress index," calculated from factors such as temperature and humidity, is 35 or higher at all observation points within the prefecture.

While Saitama Prefecture, north of Tokyo, saw the index hit 34 or higher at all of its points on Aug. 11, 2020, according to the ministry, there have been no cases to date that would warrant a special alert.

The new alert system comes on top of the existing system, which issues an alert for each area within a prefecture when the index is predicted to reach 33 or higher.

The new system was created as annual deaths from heat stroke have exceeded 1,000 in recent years in Japan.

The nation's average temperature in the summer of 2023 was the highest since the Japan Meteorological Agency began recording comparable data in 1898.

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