When we are in a medical drama or have the opportunity to go to the operating room, we will find that the doctor will cover the patient with many layers of cloth when performing an operation, and at the end, only a small piece will be revealed, which may be a round one or a square one with a hole in it.

Why is it necessary to put a cloth on the patient during surgery?
The sheets laid on the patient during surgery include the treatment towel, the center sheet and the surgical cavity towel. One of the surgical drapes is the one we see with a hole in it. In addition to these being the agreed upon therapeutic provisions of surgery, there are three considerations.

(1) Need for sterility
Without asepsis, the mortality rate of surgery is very high. When the invention of the microscope, scientists know the existence of microorganisms in nature, the concept of surgical asepsis has gradually taken root. In addition to killing most of the microorganisms on the surface of the skin through skin sterilization, surgery involves laying down a variety of green surgical towels to isolate the remaining bacteria in the air and on the body.
Even in orthopedic and cardiac surgery when applying adhesive incisional towels, if the patient has no iodophor allergy or other contraindications, the application of iodophor impregnated incisional towels[1] is also considered to prevent the occurrence of surgical infections.

(2) Thermal insulation
The temperature of the operating room is generally controlled at about 25, and after surgery and anesthesia, especially general anesthesia surgery, the patient's metabolism will be reduced by the effect of anesthesia drugs, so the heat production will be reduced, coupled with the surgery may not be able to avoid the opening of the body, or even open the belly, the intraoperative fluids need to be maintained to maintain the internal environment, which will lead to a relatively low body temperature. Sheets to a certain extent can play a role in keeping warm, and even sometimes need to use a specialized heating device to keep the patient warm.

(3) Protecting patient privacy
Doing surgery, in order to be sterile, many times the surgical area and even the whole body will have no clothing attached, that is to say, may be naked, that for the patient and the doctor, if the non-surgical area covered up, only reveals the surgical field, certainly for both sides is also a convenient, but also as far as possible to protect the patient's privacy.