The Backstreet Boys canceled their November 21 concert at Dodge Theater in Phoenix, AZ, after Nick Carter became ill that afternoon, reported concert promoter Live Nation.

There are no plans to reschedule that show. Refunds are available at point of purchase.

The group's November 22 concert in Las Vegas, NV, at Pearl Concert Theater and November 23 show in Hollywood, CA at the Hollywood Palladium took place as scheduled. However, at their Las Vegas concert, Carter was definitely showing signs of illness.

According to a report on MyFOXHouston.com, Carter, who had a 103-degree fever the day before, was forced to bow out of singing his parts during their Vegas show after straining to sing the group’s first couple of numbers. Fellow band member Howie Dorough filled in for Carter.

The shows are part of the second North American leg of the group's 2008 Unbreakable Tour, which kicked off in February and has since toured Asia, Mexico and Europe. The Backstreet Boys' first North American leg ran July 29 through September 6.