Do people need to wear masks during outdoor activities?

Wearing masks, people run on the track
at Olympic Forest Park in Beijing, on March 18, 2020. [Photo by Wei Xiaohao/chinadaily.com.cn]

3月18日，人们戴着口罩在北京奥林匹克森林公园跑步。（图片来源：中国日报网）

Medical masks and surgical masks are sufficient for normal use, and wearing multiple masks does not provide more protection, according to the guideline.
指引指出，医用口罩或医用外科口罩可用于普通防护，佩戴多个口罩并不能增加防护效果。

指引对普通公众（general public）、特定场所人员（people at specific areas）、重点人员（key population groups）以及职业暴露人员（people with occupational exposure）进行分类，并对不同场景下戴口罩提出科学建议。

这些情况不建议戴口罩

普通公众在居家（stay at home）、户外（outdoors），无人员聚集（no crowds）、通风良好（well-ventilated）的情况下，建议不佩戴口罩。

这些情况佩戴一次性口罩

The public is advised to carry along masks when in crowded places such as offices, shopping malls, restaurants, workshops and public transport. People in high-risk areas should wear surgical masks all the time when entering such places, while those in medium-risk and low-risk areas need to wear medical masks when in contact with others at the distance of less than 1 meter.
普通公众处于如办公、购物、餐厅、车间、公共交通工具等人员密集场所时，在中、低风险地区，应随身备用口罩，在与其他人近距离接触（小于等于1米）时戴口罩。在高风险地区，戴一次性使用医用口罩。

Those who have cold symptoms such as coughing or sneezing, or who live with personnel in quarantine or that have recovered from the novel coronavirus and been discharged from the hospital, are suggested to wear disposable medical or surgical masks.
对于咳嗽或打喷嚏等感冒症状者，建议戴一次性使用医用口罩或医用外科口罩。对于与居家隔离、出院康复人员共同生活的人员，建议戴一次性使用医用口罩或医用外科口罩。

这些情况建议佩戴防护口罩

People working in places such as hospitals, train terminals, airports, prisons and nursing homes need to wear surgical masks or respirators of grade KN95/N95 or above.
医院、火车站、机场、监狱、养老院等人员密集场所工作人员，建议戴医用外科口罩或符合KN95/N95及以上级别的防护口罩。

The suspected cases, confirmed cases of novel coronavirus, asymptomatic cases and those who have close contact with confirmed cases are recommended to wear surgical masks or respirators with no breathing valve graded at KN95/N95 or above. Entry personnel need to wear such masks from the moment they enter the country to the end of their required quarantine.
新型冠状病毒肺炎疑似病例、确诊病例和无症状感染者；新型冠状病毒肺炎密切接触者；入境人员(从入境开始到隔离结束)，戴医用外科口罩或无呼气阀符合KN95/N95及以上级别的防护口罩。

职业暴露人员根据工作内容及地点不同，佩戴医用外科口罩、医用防护口罩或送风过滤式呼吸防护器。