Before a doctor performs an operation, he or she will cover most of the patient's body with a green cloth. The cloth has a hole cut into it through which the doctor will perform the surgery on the patient. The medical term for the cloth that covers the patient's body is called a surgical drape, or a sterile drape, and its primary purpose is to ensure a stable, sterile environment during surgery. However, this is no ordinary cloth. Surgical drapes are sterilized at high temperatures and pressures before use.

The main reason for doing so is to ensure asepsis during surgery and to prevent the patient's wound from being contaminated and infected by bacteria during surgery. Surgery is most afraid of wound infection. By covering other parts of the patient in this way and leaving only the surgical area, the probability of infection can be greatly reduced. This requires that, doctors and nurses in the operating room must strictly follow the surgical procedures. Avoid complications caused by bacterial infection of the patient's surgical wound. Doctors and nurses should wear sterile surgical gowns, bring sterile gloves and lay sterile instrument carts and hold sterile forceps, sterile wipes, etc. before surgery.

Nowadays, operating rooms are very advanced, basically are laminar flow operating rooms, try to eliminate the possibility of airborne pathogenic microorganisms. Surgical instruments are also after high temperature and high pressure or plasma sterilization, the doctor before the operation should strictly clean both hands until the bilateral elbow joints above the part, but also wear sterile surgical gowns, masks and hats, wearing sterile gloves, all of which are to avoid bacterial infection of the patient through the surgical incision, although the doctor has done a very complete, the surgical instruments are also strictly sterilized, but if the patient's side of the disinfection of the sterility of do If the patient is not sterilized properly, it is all in vain. Before the operation, the doctor will first mark down the patient's surgical incision, along the surgical incision and the surrounding disinfection, and then began to lay layer after layer of the cloth mentioned in this question, of course, the cloth is strictly sterilized, the first is a small piece of cloth, and then a medium-sized cloth, and finally the largest piece of cloth, need to be laid on a lot of layers, only to expose the part of the surgical incision site, but also in order to avoid contamination. The surgical instruments that need to be used can then be safely placed on the sterile cloth.