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Bair Hugger Warming Blankets

Hospitals used Bair Hugger Therapy devices for decades to keep people warm during orthopedic surgery. While there is not yet a definitive link, some studies show the use of Bair Huggers during the procedures may have an increased infection risk over other warming methods. The inventor of Bair Hugger products claimed the product was faulty, and some people who developed infections filed lawsuits against 3M, the device’s manufacturer.

Did you develop complications after an operation where a Bair Hugger device was used?You might be entitled to compensation.

What is Bair Hugger Therapy?

Bair Hugger Therapy is the use of temperature management systems that use forced-air warming to prevent and treat hypothermia in patients during surgery. Dr. Scott D. Augustine invented Bair Hugger surgical equipment – which includes blankets, warming units and accessories – and sold it through his company, originally named Augustine Biomedical and Design.

Hospitals used Bair Hugger Therapy on more than 180 million patients since it was introduced in 1988, and more than 80 percent of hospitals in the U.S. use the therapy today. In 2010, 3M paid about $800 million to buy Arizant, the maker of Bair Huggers.

Augustine was one of the first to develop a method for keeping patients warm during surgery. Almost all patients become hypothermic – a condition causing the body to lose heat faster than it can produce heat – during surgery. Even mild hypothermia during surgery can lead to blood loss, infections and prolonged hospital stays.

Now, these forced air warming (FAW) blankets are at the center of controversy. Augustine says the Bair Hugger blanket should not be used in patients undergoing surgery, especially joint replacements including knee and hip replacement, because the device can spread bacteria linked to infections. He presented a number of studies he said prove these surgical blankets increase infection rates.

3M, the device's maker and marketer, said Augustine's claims are alarmist and based on faulty studies that do not conclusively prove the blankets increase infection rates.

How Bair Hugger Therapy Works

Bair Hugger warming units filter air, then force warm air through Bair Hugger disposable blankets which cover patients before, during and after surgery. The warming unit is supposed to force the air gently and evenly throughout the blanket.

Bair Hugger blankets are designed to use pressure points on the patient’s body to prevent heat from reaching areas that are at risk for pressure sores or burns. The blankets also include drain holes where fluid passes through the surface of the blanket to the linen underneath. This is supposed to reduce the risk of skin softening and reduce the risk of unintended cooling because of heat loss from evaporation.

Bair Hugger blankets are disposable in order to reduce the chance of infection transmission from one patient to another. They are not designed to enter sterile fields during surgery.

Bair Hugger Products:

Warming Units

bair hugger warming units
Warming Units
  • Model 505 warming unit
  • Model 750 warming unit
  • Model 775 warming unit

Types of Blankets

Intraoperative Blankets
  • Upper Body Model 552
  • XL Upper Body Model 523
  • Lower Body Model 525
  • Dual Port Torso Model 542
Postoperative Blankets
  • Full Body Model 300
  • Chest Access Model 305
  • Pediatric Model 310
  • Multi-Access Model 315
Pediatric Blankets
  • Small Lower Body Model 537
  • Pediatric Long Model 530
bair hugger blanket types

Underbody Series

Underbody Series
  • Pediatric Underbody Model 555
  • Large Pediatric Underbody Model 550
  • Adult Underbody Model 545
  • Spinal Underbody Model 575
  • Lithotomy Underbody Model 585
  • Full Access Underbody Model 635
  • Sterile Full Access Underbody Model 637
bair hugger underbody series

Specialty and Cardiac Blankets

Specialty and Cardiac Blankets
  • Outpatient with booties Model 110
  • Outpatient Model 111
  • Cath Lab Model 560
  • Surgical Access Model 570
  • Full Body Surgical Model 610
  • Sterile Cardiac Model 630
  • Sterile Cardiac Access Model 645
bair hugger specialty and cardiac blankets


  • Model 505 Hose
  • Model 750 Hose
  • Model 505 Filter
  • Model 750 Filter
  • Clear Drapes
  • Hose Clip
  • Sheet Clip
  • Temperature Test Kit
  • Model 505 Rolling Cart
  • Model 700 Rolling Cart
  • 241 Blood/Fluid Warming Set
bair hugger accessories

Bair Hugger's FDA History

The U.S. Food and Drug Administration (FDA) cleared the first Bair Hugger warming system in 1987 through the 510(k) premarket clearance program as a substantially equivalent device. The FDA regulates drugs and medical devices and must approve or clear devices before they enter the market. Under the 510(k) program, the FDA can clear a medical device without clinical proof that it is safe if it is similar enough to a previous device that is already on the market.

The FDA issued 12 additional clearances for Augustine Medical devices through the 510(k) premarket program from 1990-2002. After Augustine Medical changed its name to Arizant, the FDA issued two more clearances for medical devices through the 510(k) program from 2004-06.

The FDA has not issued a recall of Bair Hugger devices, but numerous adverse events have been reported to the FDA. The majority of adverse events involve burns from prolonged exposure to heat during surgery or equipment malfunctions, resulting in cold air blowing during surgery.

Bair Hugger Inventor Points out Flaws

Since resigning from his positions as chairman and chief executive of Arizant in 2002, Dr. Scott D. Augustine has campaigned against his invention. He claims Bair Hugger therapy can cause infectious bacteria to spread during orthopedic surgery.

“I am very proud of the old technology,” he said in a New York Times article. “But I am also proud to spread the word that there is a problem.”

The device’s manufacturer points to 170 studies that found forced-air warming to be beneficial to maintaining normal body temperature. However, Augustine argues that none of those studies analyzed forced-air warming during orthopedic surgery.

In a letter obtained by the New York Times, Augustine told Arizant: “The question for you to answer is the following; is Bair Hugger going to be replaced quickly and catastrophically by a mandatory recall, or do you survive a voluntary recall and live to fight another day?”

3M and Arizant

3M, formerly known as the Minnesota Mining and Manufacturing Company, bought Arizant for $810 million in 2010. It generated more than $31 billion in global sales in 2014. The company is known for inventing Post-It Notes and Scotch Tape, but has businesses in the consumer products, electronics, energy, safety, graphics, industrial and health care fields.

The company markets a variety of infection prevention products, including casts and splints, fluid warmers, hygiene monitors, drapes, masks and respirators, sterilization monitors and temperature monitors.

3M and Arizant continue to market Bair Hugger products.

3M logo

Studies on Bair Hugger and Infection Risk

Despite its popularity, some doctors are concerned about using Bair Hugger therapy during orthopedic surgery or surgeries involving implants, because those surgeries often carry a high risk of contamination. Multiple studies found forced-air warming carried a higher risk for contaminating surgical sites than other warming methods.

However, some researchers are quick to point out that many of these studies could have flaws that make them inconclusive and unreliable because they cannot prove FAW increases infection risk.

2011: Deep Joint Infection

  • A 2011 study by McGovern et al. found "a significant increase in deep joint infection, as demonstrated by an elevated infection odds ratio, was identified during a period when forced-air warming was used compared to a period when conductive fabric warming was used."

2012: Convection

  • A 2012 study by Belani et al. stated “[FAW] was found to establish convection currents that mobilized resident air from the nonsterile areas upward and into the surgical site. The clinical concern is that convection currents may mobilize underdrape contaminants into the surgical site..."

2012: Forced-Air Warming

  • A 2012 study by Legg et al. concluded "a significant mean increase in the temperature and number of particles over the surgical site when compared with radiant warming, which raises concern as bacteria are known to require particles for transport."

2013: Ventilation

  • A 2013 study concluded that excess heat from forced air warming disrupted the ventilation of air flow. Comparatively, conductive patient warming had no effect on ventilation air flow.

2013: Increased Air Temperature

  • Another 2013 study found that waste heat from a forced-air warming blanket increased the air temperature of a surgical drape, creating convection currents that created turbulence over the patient. This turbulence over the patient could draw damaging particles from below the operating table to the surgical site.

3M Defends Bair Huggers

In response to Augustine's claims and increasing numbers of lawsuits, 3M launched its own campaign to prove Bair Huggers were safe. In 2016, it published a statement pamphlet entitled "Let's Spread Good Science."

Safety evidence presented by 3M in the pamphlet includes:

  • Safety and efficacy documented in over 170 as well as more than 60 clinical trials.
  • ECRI Institute, an independent organization, found "insufficient evidence to establish that the use of FAW systems leads to an increase in SSIs (surgical site infections) compared to other warming methods."
  • Studies relied on by plaintiff's lawyers and Augustine are flawed.

"There is no evidence that forced-air warming increases the risk of infection," 3M attorney Christiana Jacxsens told Outpatient Surgery Magazine in 2015. "In its entire history, not one hospital, doctor, or medical provider has reported a single confirmed incidence of infection believed to be caused by the Bair Hugger device."

Dr. Javad Parvizi, Professor of Orthopedic Surgery, Rothman Institute at Thomas Jefferson University, analyzed the evidence presented that FAW increased infections. He said, "There is no scientific proof that the use of forced-air warming blankets lead to an increase in surgical site infection regardless of the type of surgical procedure and the type of operating room."

"False representations or facts out of context are not 'proof' of any kind, they are merely incorrect and deceptive," 3M said in response to Augustine's claims in its 2015 Claims vs. Facts pamphlet.

Side Effects of Infections

The body’s natural immune system response to infections in the blood stream can eliminate most infections. But it is difficult for the immune system to attack bacteria on metal and plastic hip or knee implants. When an infection makes it to an implant, it can multiply rapidly, causing pain, swelling, fevers and fatigue.

Deep joint infections can lead to:


Barbara Libby claimed an infection involving a Bair Hugger device caused her multiple hospital stays and surgeries.

Implant revision surgery

Tommy Walton claimed he was forced to undergo 15 revision surgeries after suffering an infection involving a Bair Hugger device.

Permanent disability

Renny Schackmann claimed to have suffered permanent physical impairment from an infection caused by a Bair Hugger device.


Timothy Johnson claimed an infection involving a Bair Hugger device caused multiple revision surgeries and amputation.


If untreated, a deep joint infection can cause death.


Patients who developed infections after surgery involving Bair Hugger Therapy filed lawsuits against the device’s manufacturer, 3M and Arizant. The lawsuits claim 3M knew about the risks for infection but did not warn healthcare providers about that risk. The lawsuits also claim 3M and Arizant attempted to conceal and discredit scientific data that could be associated with risks linked to the device.

Bair Hugger lawsuits seek damages for medical expenses, pain and suffering, lost wages and punitive damages.

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