The pop superstar performed for hours in nearly 100-degree heat Friday night at Estadio Olímpico Nilton Santos stadium in Rio de Janeiro -- and the video shows how much the soaring temperature impacted Taylor.

Keep in mind, this was the same night one of Taylor's fans, Ana Clara Benevides, died right before the show kicked off.

Video of Taylor’s scary moment was posted to X … it starts with Taylor wrapping up a song with her back to the packed crowd. She then turns to the audience, huffing and puffing as if she’s struggling to breathe. The 12-second clip ends with Taylor closing her eyes.

Her worried fans responded to the video post, sharing their concerns. One wrote, "OMG… this breaks my heart in so many levels. She’s so professional but watching her like this, my best wishes go to her.”

Another pointed out, “She is only 33 and in incredible physical shape. That she was struggling that much is really scary," while a third person remarked, “Taylor was struggling to breathe as well!!”

Due to the extreme temps, Taylor announced she was postponing her Saturday concert in Rio because the “safety and well-being of my fans, fellow performers, and crew has to and always will come first.”

Benevides complained she wasn't feeling well right before Friday night's show began, and was reportedly taken to a hospital where she died. The official cause of death hasn't been determined.