A staff member of epidemic prevention and control is seen at a residential compound, identified as a medium-risk zone for COVID-19, in Huanggu District in Shenyang, northeast China's Liaoning Province, Jan. 6, 2021. Shenyang is experiencing a strong cold wave that started on Wednesday, as the temperature dropped to near minus 20 degrees Celsius. (Xinhua/Yao Jianfeng)