It is possible to open windows and ventilate the upstairs with a confirmed patient downstairs. Although the new coronavirus can be transmitted through aerosols, outdoors, under the action of air currents, the aerosols discharged by positive patients will soon be diluted by fresh air, and the concentration is generally low and will not infect the human body. Secondly, the virus has a limited survival time in the air. Even if a positive patient may expel the virus by opening a window, the virus will die soon and people upstairs will not be infected by the virus. Once there are confirmed cases, they will all be treated in centralized isolation. Close contacts are also quarantined to isolate the source of infection. The environment where confirmed cases live will be strictly disinfected to further reduce the risk of spreading the virus. If buildings are close together or in the same building, avoid opening windows at the same time, and disinfect the building and the neighborhood. Individuals should protect themselves by wearing masks, washing their hands frequently, and avoiding crowded places.