(180617) -- CHICAGO, June 17, 2018 (Xinhua) -- People play at the Crown Fountain in Millennium Park of downtown Chicago, the United States, on June 16, 2018. The temperature here suddenly surged over 30 degrees celsius on Saturday.(Xinhua/Wang Ping) (djj)more(180617) -- CHICAGO, June 17, 2018 (Xinhua) -- People play at the Crown Fountain in Millennium Park of downtown Chicago, the United States, on June 16, 2018. The temperature here suddenly surged over 30 degrees celsius on Saturday.(Xinhua/Wang Ping) (djj)more(180617) -- CHICAGO, June 17, 2018 (Xinhua) -- People play at the Crown Fountain in Millennium Park of downtown Chicago, the United States, on June 16, 2018. The temperature here suddenly surged over 30 degrees celsius on Saturday.(Xinhua/Wang Ping) (djj)more