The metal microfibers in some athletic clothing can cause burns during MRI procedures, reports The Sacramento Bee.

“I suspect many patients are unaware of the clothing risks,” Bradley Delman, an associate professor of radiology at Mount Sinai Health System, told MarketWatch. “Even very comfortable clothing can present unnecessary risks. Safety must come first.”

The Stanford University Center for Cognitive and Neurobiological Imaging posted a warning online in 2016 on Lululemon and other popular yoga brands. The notice also warns MRI patients to beware of metal buttons in some boxer shorts and metal stays in bras.

Get the full story at The Sacramento Bee.