Jessica Simpson vomited while visiting US sailors earlier this month.

The blonde singer was paying a visit to troops on board the USS Harry S. Truman in the Persian Gulf on October 1 and suffered from sickness because of the heat in the region.

A source told US Magazine: "She flew in on a helicopter and had three Red Bulls with no water. Then she complained it was too hot out.

"She only sang one song, then vomited. She was dehydrated and got sick before she performed - and even got an IV. The doctor told her not to sing, but she did anyway."

Despite her sickness, Jessica auditioned for a soldier to perform a duet with her at the Rockefeller Christmas Tree Lighting event in ceremony - with Aviation Boatswain's Mate 3rd Class John Britt winning the prize.

He said: "It's a once in a lifetime opportunity, and I'm honoured to be part of it. I'm excited to be able to represent Truman, as well as the entire Navy. My family and shipmates are proud of me."