Instead of stopping and rushing to help her, Iggy continued to perform, weakly adding, "Somebody put the medic up here."
Other backup dancers rushed to their friend on the ground, while Iggy continued to sing.
After another 15 seconds, the music finally stopped.
Eventually, medics drove an ambulance on stage to remove the dancer, who has since recovered.
Fans have completely blasted Iggy for not halting her performance immediately.
Later, Iggy took to her Instagram story to address the issue.
"Hey guys. I just want to let everyone asking know my dancer is OK. The lights and heat caused her to have a seizure. She is backstage feeling much better," she said.
"Also, for what it’s worth in regards to the backup dancer. One, I thought she had just fallen/twisted her ankle. And it may sound harsh, but you keep singing until the music stops and ask for a medic, which is what I did.
"Two, we are all really shaken up by what happened and just thankful she is OK.
"Three, I know it’s easy to make memes of someone 'passed out' but someone having a seizure isn’t funny, it’s really scary! I hope my fans do not repost some of the memes I’m seeing about my dancer."
Iggy then launched into a massive rant to her fans, saying she feels "worn down" by the constant criticism.
"Sometimes I really feel exhausted by the world, it feels like anything I do becomes an opportunity for people to tell me why I’m s***, why my music sucks, my clothes are ugly, why I don’t matter or why I’m a horrible person," she said.
"I’m worn down. The last four years are just me existing in a world where I can do nothing right and it’s hard not to feel like 'what’s the point' and keep motivated.
"Everyone is just trying to make it through their day. Could we be a little kinder to each other? Seeing how much people enjoy being awful to one another is depressing."