The Real Reason It's Cold in the OR

Most people think operating rooms are cold to prevent infections. Experts say not only is that assumption false, but lower temps tend to increase the rate of surgical infections. The real reason it’s cold in the OR is for the comfort of the surgical staff. Nurses and surgeons get hot under their protective equipment and the bright surgical lights, so like cooler temperatures to feel comfortable and to perform at their best.

But, according to MedPage Today, it’s not the best environment for the patient who should be the most important person in the room. Dr. Max Feinstein, chief resident of teaching at Mount Sinai Hospital in New York City, is an anesthesiologist who isn’t fond of cold ORs. He says that anesthesia redistributes blood from the core of the patient to his or her extremities which accelerates heat loss. This isn’t helped by cold surroundings, he says, adding that for every decrease in core temperature of 1.9 degrees Celsius, there is a threefold risk of surgical infection.

When your body is in a cold environment, it constricts blood vessels so as not to waste heat, a process called thermoregulation, says Verywell Health. This increases the risk of infection because blood flow is restricted and can’t supply adequate oxygen to tissues. Secondly, your immune system is weakened by hypothermia, or a drop in your body temperature below normal levels. Therefore, maintaining normal body temperature during surgery will help your body fight infection.

Furthermore, hypothermia can lead to cardiac issues.

“In the worst case we worry about a cold temperature actually precipitating a myocardial infarction,” says Feinstein. “Cold temperatures are also associated with increased rates of bleeding in the operating room, so this is of course a problem for the patient and it makes it more difficult for the surgeon to just do surgery if the surgical field is filled with blood.”

Feinstein says there are also studies that show decreased core body temperature in the OR is associated with longer stays in the post-anesthesia care unit.  Anesthesiologists try to keep patients warm by using a forced air-warming device that is essentially a fancy blow dryer that delivers very warm air through a blanket that surrounds the patient. It’s called a Bair Hugger and is placed appropriately on the body depending on where the surgery is taking place. Anesthesiologists can also keep patients warm by delivering warm IV fluids.

Feinstein says that he doesn’t blame surgeons for preferring a cold OR since they are wearing a gown and operating under hot lights. One study found that surgeons prefer the room temperature to be 19 degrees Celsius (66.2 degrees Fahrenheit) while anesthesiologists like the room to be 21.5 degrees Celsius (70.7 degrees Fahrenheit).

To protect yourself in an OR, ask that the room be kept at a reasonable temperature, says Verywell Health, and let the staff know when you are cold. While surgeons and the other OR staff want to be comfortable, their priority is your comfort.