Heating equipment is placed at a Covid-19 testing point on Tuesday in Tianjin municipality, which started a new round of citywide nucleic acid testing for its 13.9 million residents from 6 p.m. that day. Photo: VCG

A medical worker takes a swab sample from a Tianjin resident on Tuesday night. It’s the sixth round of citywide testing in the city since Thursday. Photo: Zhu Chuantao (intern)/Caixin

A child wears thick winter attire while waiting to get tested. Due to the cold wave, the temperature in the city dropped sharply, 8-10 degrees Celsius lower than that of Monday. Photo: Zhu Chuantao (intern)/Caixin

A woman pushes an elderly resident in a wheelchair to the testing point to take a nucleic acid test in Tianjin’s Nankai district. Photo: Zhu Chuantao (intern)/Caixin

Residents wear thick winter head gear to protect themselves from the cold weather while waiting in line. Photo: Zhu Chuantao (intern)/Caixin

Residents in Nankai district make their way to the testing site to get swabbed. Photo: Zhu Chuantao (intern)/Caixin

A medical worker carries samples out of a Covid-19 testing point on Tuesday night. Photo

Students from Tianjin University line up to get swabbed on Tuesday night in Jinnan district. The city reported 870 local cases for Tuesday, the highest daily count this month, of which 866 are asymptomatic. Photo: VCG