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Bair Hugger Infection Lawsuit

The Bair Hugger warming device has been a popular medical device used in hospitals for years. It is used to keep patients warm during surgeries, which helps prevent hypothermia and other complications. However, studies have suggested that the use of Bair Hugger warming devices during joint replacement surgery may increase the risk of infection.  These studies spawned thousands of lawsuits that evolved into the Bair Hugger class action lawsuit.

What Is the Bair Hugger Warming Device?

The Bair Hugger warming device is a forced-air warming system that was first introduced in 1987. It is a portable device that blows warm air through a disposable blanket, which covers the patient during surgery. The device is designed to maintain the patient’s body temperature, which helps reduce the risk of hypothermia and other complications.

The Bair Hugger was created in the 1980s by Augustine Medical, Inc., which was later acquired by Defendant Arizant Healthcare, Inc. In 2010, Defendant 3M Company purchased Arizant, including the Bair Hugger product line. The Bair Hugger is designed to keep patients warm during surgical procedures by blowing warm, forced air over the patient. It consists of a portable forced-air temperature management unit and a disposable Bair Hugger forced-air blanket, with 25 different styles available that vary in size and coverage, including partial or full coverage of the patient’s body, and some are used underneath the patient. The manufacturer markets Bair Huggers as a warming solution that can be used for various patients, from pediatric to geriatric, and for both short and long procedures. The marketing slogan for Bair Huggers is “Everyone Deserves a Hugg™,” emphasizing its suitability for everyone.


Despite its widespread use in hospitals across the country, the manufacturer has been accused of misrepresenting the safety and effectiveness of the Bair Hugger, which can lead to significant and preventable infections for patients.

The Bair Hugger lawsuit, which we will talk about in a minute, accuses the manufacturer of knowingly concealing the risks associated with the Bair Hugger and actively misleading the public, medical community, and FDA through false advertisements and statements.

Bair Hugger and Joint Replacement Surgery

Bair Hugger warming devices have become particularly popular during joint replacement surgeries, such as knee and hip replacements. These surgeries are typically lengthy and can last for several hours, during which time the patient is exposed to cold temperatures. Maintaining the patient’s body temperature is critical during these procedures, as it can help reduce the risk of infection, improve wound healing, and promote faster recovery.

However, studies have suggested that the use of Bair Hugger warming devices during joint replacement surgery may increase the risk of infection. This is because the device’s forced-air system can blow bacteria and other contaminants from the floor of the operating room onto the surgical site. The warm air can also disrupt the flow of air in the operating room, which can cause bacteria to circulate more easily.

What Is the Problem with the Bair Hugger?

The hot air produced by the Bair Hugger builds up in areas around the patient, particularly under the surgical drape covering the patient, and escapes either from under the surgical drape below the level of the surgical table or at the head end of the surgical table. When the hot air escapes, it forms a current of air that is forced downward toward the floor of the operating room.

The warm air from the Bair Hugger causes the air to pick up bacteria and other pathogens from the floor of the operating room, and when the still-warmer-than-the-operating-room-temperature air begins to rise after leaving the air current caused by the Bair Hugger, the bacteria and other pathogens picked up from the floor of the operating room are deposited into the surgical site. As a result, this can and has led to significant and preventable infections for patients, including the plaintiff.

Defendants, the manufacturers and/or suppliers of the Bair Hugger, have been aware of the danger of infections present in the system for many years. They have continued to misrepresent the safety of the Bair Hugger in advertisements, statements to healthcare providers, and in submissions to the FDA. They made misrepresentations to the FDA when they claimed the Bair Hugger’s filtration system met the strict High Efficiency Particulate Air (“HEPA”) standards when it only removed at most 65% of particles, not the required 99.97%. They also knew of the contamination of the airflow paths of the Bair Hugger since at least 2009.

The medical community has published numerous peer-reviewed studies detailing the dangerous defects of the Bair Hugger. A prudent manufacturer would have taken their knowledge and redesigned and improved their product. However, instead of fixing these problems, Defendants continued to provide false and misleading information to the public and healthcare community, focusing on the rate at which air moves in the operating room and drawing attention away from the real issue with the Bair Hugger warming systems, which is the heat of the air that has been warmed by the Bair Hugger and is forced out onto the floor and circulates pathogens and infectious agents into the surgical site when it rises.

For instance, in advertisements on the Defendants’ Bair Hugger website, they made inaccurate claims that the air velocity within the operating room is many times stronger than that of a forced-air warming blanket and that the air emerging from the blanket is directed downward by the surgical drape and emerges under the operating room table, and it is drawn away through the laminar system’s return air inlets. They also claimed that warm air rising above the Bair Hugger blanket could interfere with the downward laminar flow toward the surgical site. They knew or should have known that these statements were false.

Bair Hugger Class Action Lawsuit

The link between Bair Hugger warming devices and joint replacement infections has led to a wave of lawsuits against 3M Company, the device’s manufacturer. Patients who have developed infections following joint replacement surgery are seeking compensation for their injuries, alleging that 3M Company failed to adequately warn them of the risks associated with the device.

The first Bair Hugger lawsuit was filed in 2013 by a man who developed a serious infection following hip replacement surgery. Since then, thousands of lawsuits have been filed against 3M Company, with many more expected in the coming years.

In these lawsuits, plaintiffs allege that 3M Company knew or should have known about the increased risk of infection associated with Bair Hugger warming devices, but failed to adequately warn patients and healthcare providers. They also allege that the company continued to market and sell the devices, despite being aware of the risks.

The Bair Hugger class action lawsuit (MDL) was formed in 2015 by the Judicial Panel on Multidistrict Litigation. The MDL consolidated numerous lawsuits filed by patients who had developed infections after undergoing joint replacement surgery in which a Bair Hugger warming device was used.

As of 2023, the Bair Hugger MDL includes over 6,000 individual cases against 3M Company, the device’s manufacturer. The cases have been consolidated in the U.S. District Court for the District of Minnesota under the oversight of Judge Joan N. Ericksen.

Judge Ericksen dismissed all of the claims in 2019 because she didn’t think the expert testimony was reliable.  In August 2021, the 8th Circuit overturned the ruling on appeal and the U.S. Supreme Court refused to hear the case. The 8th Circuit was not excited about the current state of the science that supported the plaintiffs’ evidence. The appeals court acknowledged weaknesses in the factual basis for the medical experts’ general-causation opinions.

Ultimately, however, the appellate court found that these weaknesses were a matter for cross-examination because the experts’ general-causation opinions were not fundamentally unsupported to be excluded. In other words, the 8th Circuit judges basically said that if they were on the jury they would not be convinced by the plaintiffs’ causation evidence, but the evidence was at least good enough for it to be presented to a jury anyway.

So now we are back to square one as the MDL moves towards a bellwether test trial.

3M’s Response

3M has vigorously defended itself against these lawsuits, arguing that there is no scientific evidence to support the claim that Bair Hugger warming devices increase the risk of infection. The company has cited numerous studies and expert opinions that support the safety and efficacy of the devices.

In a statement, 3M Company stated that “patient safety is our top priority, and we stand behind the safety and efficacy of our products.” The company has also pointed out that Bair Hugger warming devices are widely used in hospitals around the world and have been approved by regulatory agencies, including the U.S. Food and Drug Administration (FDA).

Who Qualifies for a Bair Hugger Lawsuit?

Our national product liability lawyers are once again actively seeking Bair Hugger infection cases from qualified plaintiffs who meet certain eligibility criteria. Individuals who qualify for a Bair Hugger lawsuit include anyone who underwent a surgical procedure during which the Bair Hugger device was used and subsequently suffered a post-surgical infection.

Post-surgery infections related to the Bair Hugger device occur most frequently in joint replacement surgeries, such as knee replacement or hip replacement procedures. Bair Hugger warming devices are used in 80% of these type of joint replacement surgeries. Also, the risk of infection from the Bair Hugger during knee and hip replacement surgery is particularly high because they are long, invasive operations.

Contact Our Bair Hugger Lawyers to File Your Case

The national product liability attorneys at Miller & Zois are currently accepting new Bair Hugger surgical infection cases. If you think you developed an infection from a surgery in which a Bair Hugger device may have been used, contact us today for a free consultation. Calls us at 888-322-3010 or contact us online.