Medical workers prepare to perform swab test to a resident in Fengtai District of Beijing, capital of China, June 15, 2020. Beijing has strengthened community-level disease prevention and control in response to the resurgence of domestically transmitted COVID-19 cases. (Xinhua/Li Xin)

A member of the Beijing Blue Sky Rescue(BSR) team takes off the protective gloves after a disinfection operation at the Yuegezhuang wholesale market in Beijing, capital of China, June 16, 2020. Beijing has strengthened community-level disease prevention and control in response to the resurgence of domestically transmitted COVID-19 cases. (Xinhua/Chen Zhonghao)

A member of the Beijing Blue Sky Rescue(BSR) team is seen covered with sweat when taking off his protective suits after a disinfection operation at the Yuegezhuang wholesale market in Beijing, capital of China, June 16, 2020. Beijing has strengthened community-level disease prevention and control in response to the resurgence of domestically transmitted COVID-19 cases. (Xinhua/Chen Zhonghao)

Medical workers perform swab test to a resident in Fengtai District of Beijing, capital of China, June 15, 2020. Beijing has strengthened community-level disease prevention and control in response to the resurgence of domestically transmitted COVID-19 cases. (Xinhua/Li Xin)

Sweat is seen inside a medical worker's goggles in Fengtai District of Beijing, capital of China, June 15, 2020. Beijing has strengthened community-level disease prevention and control in response to the resurgence of domestically transmitted COVID-19 cases. (Xinhua/Li Xin)

Volunteer Wang Yue wipes the sweat from her forehead as she works at the entrance of a community in Haidian District in Beijing, capital of China, June 16, 2020. Beijing has strengthened community-level disease prevention and control in response to the resurgence of domestically transmitted COVID-19 cases. (Xinhua/Ren Chao)

A member of the Beijing Blue Sky Rescue(BSR) team wrings sweat out of the clothes after a disinfection operation in Beijing, capital of China, June 16, 2020. Beijing has strengthened community-level disease prevention and control in response to the resurgence of domestically transmitted COVID-19 cases. (Xinhua/Chen Zhonghao)

Members of the Beijing Blue Sky Rescue(BSR) team take a rest after a disinfection operation at a community in Fengtai District in Beijing, capital of China, June 16, 2020. Beijing has strengthened community-level disease prevention and control in response to the resurgence of domestically transmitted COVID-19 cases. (Xinhua/Chen Zhonghao)

Volunteer Wang Yue (R) checks a resident's body temperature at the entrance of a community in Haidian District in Beijing, capital of China, June 16, 2020. Beijing has strengthened community-level disease prevention and control in response to the resurgence of domestically transmitted COVID-19 cases. (Xinhua/Ren Chao)