Rihanna was doing a duet with Chris Brown during a concert at the Acer Arena in Sydney, Australia where she almost fainted.
Chris andRihanna were singing "Umbrella" on stage together when Rihanna stopped singing and started to act as if she couldn't breath.
It got so bad that she wobbled off stage where paramedics were called. No one really knows what happened, but hopefully everything is OK and Rihanna is feeling better!
UPDATE: Rihanna is doing well! Her rep released a statement saying, "It was very hot at the venue, so after Rihanna's set was over, she went off stage to sit down, catch her breath and have some water. She is perfectly healthy and will be at her show tomorrow."