Taylor Swift has been seen struggling to breathe in footage from her Eras Tour concert in Rio, Brazil, where a fan died from cardiac arrest.
Video footage showed the singer taking multiple breaths at the end of a song while performing at the Nilton Santos Olympic Stadium over the weekend.
On Friday (local time), a fan died after the concert took place during what was considered extreme temperatures at the venue, which were believed to have reached around 59 degrees, according to the country's heat index.
Ana Clara Benevides, 23, became unwell and later died in hospital.
"The decision has been made to postpone tonight's show due to the extreme temperatures in Rio," Swift wrote on Instagram about two hours before she was to go on stage on Saturday.
"The safety and well-being of my fans, fellow performers, and crew has to, and always will, come first."
The 11-second clip which was shared to TikTok and has amassed over eight million views saw many fans concerned Swift was unable to perform comfortably in the heat.
She was seen hurriedly taking several deep breaths before starting another of her hit songs.
"I really hope she is okay. She has to take care of herself because it's that hot," one wrote online.
"I can't imagine the heat on her with all the light on top of the already hot environment," another said.
Fans at the venue complained after security and staff had refused to allow any of them to take water bottles inside.
In the wake of Benevides' death, Justice Minister Flavio Dino announced the government would issue a directive allowing water bottles to be brought into concerts, Reuters reported.