In general, the health code will only be recognized as a spatio-temporal companion if it stays in the middle and high risk area for more than 4 hours, and the spatio-temporal companion is in the same spatio-temporal grid as the confirmed patient within 14 days, usually taking 800 meters by 800 meters as the detection range, and the * * * stay time exceeds 10 minute.
You don't need to stay for a long time, but as long as you pass through that place, your travel code will turn yellow, because once you pass through a dangerous area or a place with an epidemic, your mobile phone signal will automatically sense your signal. In this case, your travel code will turn yellow by itself, and only after 14+7 isolation and nucleic acid preparation will it turn green. So I also want to remind you not to pass by in the risk area, but to make a detour.