It is possible that the razor in the barber store may cause the patient to be infected with AIDS, but the probability is very low unless the razor scrapes the patient’s skin in the process of shaving the AIDS patient, leaving the blood of the AIDS patient on the razor, and the razor is not disinfected. If the razor is then used to shave a healthy person, the blood left on the razor will enter the healthy person’s body through the broken skin, thus causing the healthy person to become infected with AIDS, so the probability of this is relatively low, but one should still be vigilant. Invasive procedures such as tooth extraction, tattooing, eyebrow tattooing, teeth cleaning, pedicure, etc. should be avoided in informal places outside.