After being yelled at by an angry vendor in front of a garlic sprout stall, Zhang Na was left weeping.

She turned away and used her right hand to wipe away the tears, hoping no one had seen her.

The 41-year-old felt ashamed and embarrassed. However, as she was standing beside several stalls at a large vegetable wholesale market in Qiaoxi district, Shijiazhuang, capital of Hebei province, she had nowhere to hide.

The city, hit by a rising number of COVID-19 cases since the start of this year, has been under lockdown for about two weeks, with transportation services suspended and residents ordered to stay home.

Zhang, an office clerk, has been transferred to work in outdoor areas at the market to prevent infection. Her duties involve monitoring disinfection measures taken at the stalls.

Despite wearing a long, black down-feather coat, she was struggling to keep warm after working outdoors all morning in a temperature of about 3 C.

"The cold is nothing compared with all the work we need to do to ensure sufficient supplies of agricultural produce are delivered smoothly," she said.

Vehicles entering the market are disinfected and the stalls have to be sanitized at least four times a day.

Zhang encountered the angry vendor on the morning of Jan 11 in a passageway at the market, where she was inspecting anti-virus work.

The vendor complained that his vegetables bought from outside the city had been spoiled by the cold because the trucks transporting them were waiting in line for a long time to pass through checkpoints.

Since the local outbreak emerged, certificates have been required for drivers and their vehicles before they can pass through checkpoints on roads linking the city with other areas.

In addition, everyone entering the market must produce a recent negative nucleic acid test result and have their temperature and ID card checked.

Zhang said, "These are not normal times and we've hardly had any rest in helping businesses avoid infection." She added that her colleagues have a similar heavy workload.

"However, I could understand the vendor being a little anxious about his vegetables, because spoiled produce would cause him to lose money," she said.

"Some vendors have faced similar situations－this was inevitable when the new measures were introduced, but most traders have been understanding, as we are all involved in the fight against the virus."