This year is going to be another hot summer. According to the seasonal forecast by the Japan Meteorological Agency, the temperature in the summer of 2025 (June to August) is expected to be higher than usual nationwide. June marks the 20th anniversary of the Ministry of the Environment’s proposal of “Cool Biz” in 2005. This “Cool Biz” is a compound word of “cool” and “business”. The introduction of Cool Biz resonated with businessmen who felt uncomfortable wearing ties in the summer. The Hawaiian traditional costume, the muumuu, has an air inlet and outlet. Similarly, traditional costumes such as the Indian sari and the Middle Eastern thobe have an open waist and an air passage that passes from the feet to the neck. This air passage increases the air flow between the skin and the clothing, expands the surface area for sweat dissipation, and is the basis of a mechanism that effectively cools the body. If you sweat well, your resistance to heat stroke will increase. These traditional costumes can be said to be the crystallization of the wisdom of the people.
Not only folk wisdom, but also the power of science has come to give people a sense of coolness. In Japan, summer clothing has progressed from ties to casual wear. This trend has accelerated, and the boundary between everyday clothes and office wear has become even more blurred. This year, Aoyama Shoji will launch a business T-shirt called the “Cool Office T-shirt.” The material has a glossy texture on the surface of the fabric, and feels cool to the touch. There is also a problem. Even if T-shirt sales increase, the profit margin will not increase. Of course, they are also considering ways to increase profits. Aoyama Shoji says that sales of heavy clothing such as jackets have decreased and profit margins are falling. Instead, they seem to be taking a two-pronged approach of focusing on custom-made suits, which have a higher unit price.
As global warming progresses, measures against heatstroke have become mandatory. There has been a trend in measures against extreme heat from the stage of seeking comfort to ensuring safety. In particular, measures are being taken at companies that work is done outdoors. Taisei Corporation places emphasis on the “heat index (WBGT)” calculated based on temperature and humidity at each construction site. WBGT is an index that reflects four elements: temperature, humidity, radiant heat, and ventilation. Various industries are also coming up with creative solutions. ANA is expanding the use of fan-equipped vests developed with Midori Anzen, a company that makes work clothes. Rival airline Japan Airlines provides vests equipped with Peltier elements, a type of semiconductor that changes temperature when electricity is passed through them, to ground handling staff who are responsible for ground operations. It seems that each company is racking their brains to provide an environment that employees can work comfortably in the heat.
