3M / Bair Hugger Forced-Air Warming Blanket Infection Litigation
Case Overview
The Bair Hugger is a forced-air warming system used in hundreds of thousands of surgeries annually in the United States to maintain patient body temperature during procedures. Plaintiffs in this MDL allege that the device draws in contaminated floor-level air — laden with bacteria and other pathogens — and recirculates it across the sterile surgical field via warm air currents, significantly increasing the risk of deep periprosthetic joint infections (PJIs). These infections, which occur around implanted hip or knee prosthetics, can be catastrophic, requiring multiple revision surgeries, prolonged IV antibiotic treatment, and in some cases amputation. The litigation began in earnest after a prominent 2015 study published in the Journal of Bone and Joint Surgery raised alarms about infection rate disparities between hospitals using forced-air warming versus conductive warming blankets.
3M has vigorously contested the scientific evidence, and in 2019 the MDL court granted summary judgment in 3M's favor in the consolidated 'general causation' bellwether track, ruling that plaintiffs had not presented sufficient expert evidence to establish that Bair Hugger caused infections. Plaintiffs appealed, and the Eighth Circuit Court of Appeals reversed the ruling in 2021, reinstating thousands of cases and finding that the district court had applied too strict a standard in excluding plaintiffs' experts. The litigation has continued since then, with individual cases proceeding and ongoing disputes over expert testimony, making this one of the most complex and long-running medical device MDLs in the country. No global settlement has been reached as of 2025.
Who May Qualify
Patients who underwent orthopedic surgery — particularly hip or knee replacement — in which a 3M Bair Hugger forced-air warming blanket was used, and who subsequently developed a deep periprosthetic joint infection (PJI) requiring additional surgery, hospitalization, or other serious medical intervention.
Frequently Asked Questions
How do I know if a Bair Hugger was used in my surgery?
You can request your surgical anesthesia or nursing records from the hospital where your procedure was performed. These records typically document all warming devices used during surgery. Many attorneys handling these cases can assist in obtaining and reviewing your medical records at no initial cost.
Has 3M settled the Bair Hugger lawsuits?
As of 2025, no global settlement has been reached in the Bair Hugger MDL. Individual cases have resolved on various terms, but the bulk of the litigation remains active following the Eighth Circuit's 2021 ruling reinstating thousands of cases. Plaintiffs' attorneys continue to push toward trial.
What injuries are covered in the Bair Hugger lawsuit?
The lawsuits focus specifically on deep periprosthetic joint infections following hip or knee replacement surgery performed with a Bair Hugger device in use. Qualifying injuries typically include infections requiring revision surgery, long-term IV antibiotics, implant removal, or amputation.
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