By Thomas Rosenthal

Nashville, Tenn.—When Jill Byrne, MSN, RN, CNOR, transferred back to the OR almost 10 years ago, she quickly saw that the surgeons and everyone else on her team were losing their cool.

With all of the equipment, protective gear, the number of surgical staff, and a change in OR thermostat settings, the OR had become a much hotter place to work since the last time she was a surgical nurse. After almost every procedure, one surgeon in particular emerged from the OR drenched in sweat, she recounted.

Ms. Byrne, a trauma surgery team member, while completing her PhD program at the Frances Payne Bolton School of Nursing at Case Western Reserve University, in Cleveland, was concerned about the effects of heat stress on the surgeon as well as her fellow team members.


Heat stress can affect peak performance and critical thinking. She said her PhD research has shown that regardless of a surgeon’s education or skill level, heat stress can create the potential for cognitive decline for procedures longer than 90 minutes.

She’s heard anecdotal stories of surgeons suffering from heat stress ordering the incorrect medication postoperatively or being momentarily confused about details of the procedure just performed, she recounted.


Being too hot also means the surgeons take breaks to rehydrate after the surgical procedure, creating distractions in workflow that can lead to an interruption in communication—another area for error, she said.

In addition, tempers are shortened during surgery because of heat stress. That leads to more incivility, she said. Team members may have a hard time maintaining their composure, heightening tension in an already tense environment.

“When you look at the combined effects caused by heat stress, it becomes clear how team collaboration, communication and the overall engagement can be disrupted,” said Ms. Byrne, who is writing her PhD thesis on the physiologic and psychological effects of heat stress.

Everybody complains about the temperature, but Ms. Byrne, with her concern over OR heat stress growing, decided to do something about it.


Using leftover surgical drape material, Ms. Byrne, on her own time at home, designed and hand-sewed lightweight, disposable cooling vests. Worn over scrubs and under the surgical gown, the vests have pockets designed to hold reusable ice packs close to sensitive areas near major blood vessels, such as the heart, neck and spine, to cool the body without interfering with mobility. The ice packs provided adequate cooling for two hours before they needed to be changed.

The first time the surgeon on her team wore the vest, he emerged from the OR with his scrubs completely dry, Ms. Byrne recalled. And he did not have to stop to rehydrate himself as often.

“The empirical results were dramatic,” Ms. Byrne said. “The surgeon went from a very focused, short-tempered individual to actually very pleasant. The whole room noticed the changed mood.”


So did others. Word spread with reports of how much more comfortable the surgeon felt during procedures. Other hospital staff began asking her for their own vests, she said. That was more than nine years ago.

A new surgical vest may help surgical staff from experiencing heat stress and its negative physiologic effects.

“I personally sewed approximately 500 vests over a seven-year period of time,” she said.

Several years ago, Ms. Byrne contacted Cardinal Health about manufacturing her vest. That led to Ms. Byrne and her hospital’s leadership working with the Dublin, Ohio–based health care company to produce the vests commercially. Cardinal Health launched its CoolSource cooling system vest based on Ms. Byrne’s invention at the 2019 Association of periOperative Registered Nurses (AORN) Global Surgical Conference & Expo.


Conventional wisdom once held that the OR was cold. The thermostat was previously set for the surgeon’s personal comfort level, Ms. Byrne said. The OR ambient temperature is now determined by strictly regulated standards enforced by the hospital’s engineering department intended to protect patients from developing multiple problems associated with hypothermia.

The Joint Commission , for example, recommends an OR temperature range between 68° F and 75° F.

“It’s estimated that 20% of surgical patients experience unintentional hypothermia, which is a core body temperature dropping below 36° C, potentially increasing those perioperative complications which could be delayed wound healing, surgical site infection or surgical blood loss,” Ms. Byrne said in a recent webinar, “The Heat Is On: Understanding the Impact of Heat Stress on OR Staff’s Physiological and Psychological Wellness” ( or-manager-webinars).

“Increasing the OR ambient temperature is recognized as a common strategy to address the potential harm that a patient may receive hypothermia; then that can also cause a lot of heat stress for anyone working in that unique situation,” Ms. Byrne said.

“Regulating ambient temperatures to protect those vulnerable sedated patients from hypothermia may be warm for the surgeon, but their elevated body temperatures predispose the sterile surgical field to contamination because they sweat—and that drips onto the field or even into the patient’s incision. That increases the incidence of hospital-acquired infection, which can lead to an increased length of stay,” she said.

Ms. Byrne said when she had previously worked in the OR, the staff wore cloth reusable gowns that did not trap body heat.

With the growing awareness of hospital-acquired infections, particularly surgical site infections, surgical staff comfort was sacrificed to the requirement that they wear tightly woven, impervious clinical gowns that served to prevent bacterial contamination of the patient.

Then there were the layers of personal protective equipment for the protection of the clinicians themselves from fluids and pathogens prevalent during procedures. “The materials used in the garments to protect surgeons and surgical staff can prevent heat and moisture from escaping, and, combined with a little physical activity, an increase in the heat metabolic production leads to heat stress,” Ms. Byrne said.

All of this surgical clothing, plus required headgear and face masks, affect OR staff comfort and their internal body temperature.

Ms. Byrne said the equipment and lighting in an OR add to the heat. Also, up to a dozen surgical staff members grouped together for hours at a time, each generating their own heat, can add to the rise in temperature and tempers.

“When surgical staff experience heat stress, adverse physiological responses can result,” Rosemarie Squeo, RN, BSN, MA, of Cardinal Health, wrote in “Heat in the OR and the Impact on Surgical Staff,” a continuing medical education program presented at the AORN meeting.

Ms. Byrne said her invention of the cooling vest led her to a PhD program to research the physical and psychological effects of heat stress.

At the AORN conference, Ms. Byrne said hundreds of her colleagues tried on the cooling vest. She was the featured speaker at a symposium. She said when her talk was greeted with applause, including from AORN leadership, there was pride that the innovative solution to a problem plaguing the OR for years was from a fellow nurse.

Ms. Byrne said it was a euphoric culmination of nearly 10 years of work.

Ms. Byrne reported a financial relationship with Cardinal Health regarding the sale of the cooling system vest.