Lady Gaga had to get emergency care in Colorado due to the altitude, but she was well enough to take a selfie while she wore an oxygen mask.


A lot of artists struggle with shows in high altitudes if they aren't prepared. In 2013, Carrie Underwood took a photo of herself huffing oxygen while in Colorado. In 2012, Tracy Morgan was in Utah when he fainted after giving an acceptance speech at the Sundance Film Festival.