(201229) -- BEIJING, Dec. 29, 2020 (Xinhua) -- A member of staff is on patrol inspection at the boiler room of a heating service station in Wangjing, Chaoyang District of Beijing, capital of China, Dec. 29, 2020. China's meteorological authority on Tuesday renewed an orange alert, the second highest in a four-tier warning system, for a cold wave as a strong cold front has been sweeping across most parts of central and east China from Monday. (Xinhua/Chen Zhonghao)