Aerial photo taken on Jan. 6, 2021 shows water flowing in a section of the Halha River in the city of Arxan of Hinggan League, north China's Inner Mongolia Autonomous Region. Despite Arxan's frigid winter cold, this geothermally-affected section of the Halha River never freezes even when the temperature drops to as low as minus 40 degrees Celsius. (Xinhua/Li Zhipeng)