People cool off under water sprays at Chuo-Ku in Tokyo, Japan, on Aug. 3, 2018. (Xinhua/Du Xiaoyi)

People cool off under water sprays at Chiyoda-Ku in Tokyo, Japan, on Aug. 3, 2018. (Xinhua/Du Xiaoyi)

Children cool off in the fountain at Tokyo Station in Tokyo, Japan, on Aug. 3, 2018. (Xinhua/Du Xiaoyi)

A father and his children cool off in the fountain at Tokyo Station in Tokyo, Japan, on Aug. 3, 2018,.(Xinhua/Du Xiaoyi)

A girl cools off in the fountain at Tokyo Station in Tokyo, Japan, on Aug. 3, 2018. (Xinhua/Du Xiaoyi)