Hyeri has shared the complete backstory behind a fainting incident that happened during her time with Girls' Day, giving fans insight into what actually led to the shocking moment.

In a recent YouTube video, the idol-turned-actress recalled the circumstances that led to the collapse. She explained that she had competed in curling at the Idol Star Athletics Championships, and the physical exertion left her feeling unusually cold. Despite the cold symptoms, she didn't realize she was getting sick until she got home and couldn't warm up even after turning up her electric blanket to high temperatures.

Hyeri went to the hospital and was diagnosed with an illness, but there was a problem: she had a scheduled music show performance coming up. "If we pre-recorded, they could have aired the recording, but the timing didn't work out," she explained. "We were too busy. So we performed live."

Performing while ill proved to be too much for her body to handle. Hyeri described the moments leading up to the collapse: before taking the stage, she kept lying down until the last possible moment because she felt unable to perform. Once she went on stage and started the first verse, her body simply wouldn't cooperate. "I couldn't remember the choreography when I had to raise my arm," she recalled.

As the performance continued, her condition worsened. "My face was soaked with sweat," Hyeri said. When she finally sat down at the end of the performance, she felt herself relax—but that's when nausea set in. "I felt like I was going to vomit. Then I collapsed."

The incident was significant enough that it still comes up in online searches, showing how much it impacted fans at the time. Hyeri's candid explanation reveals the pressure idols face to perform regardless of their physical condition, and the difficult decisions entertainment companies sometimes have to make when schedules don't allow for alternatives.