Ananova:

Busted's James Bourne has collapsed with heat stroke during the boy band's US tour.

The singer fell ill after the air conditioning unit packed in on the tour bus, says the Daily Mirror.

An emergency doctor had to be called in after James, 20, and his bandmates were left sweltering in temperatures of 110 degrees when the unit packed up in Colarado.

Charlie Simpson, 19, and Matt Jay, 21, managed to keep their cool, but the heat became too much for James, who became badly dehydrated.

The Mirror quotes a source: "It was a nightmare for James. The heat was horrific and the boys were already tired from working so hard.

"It was a typical case of heat stroke - feeling faint, the shakes, a terrible headache. Obviously it can be a very serious illness so a doctor was called immediately to check he'd be OK.

"Once James had been looked over, he was told to get plenty of rest and drink lots of water. The bus continued without air con until it arrived at the next city on the route. Thankfully, James recovered fine. He's a real trouper."