Blaine begins upside down stunt

US illusionist David BlaineDavid Blaine has begun another endurance challenge - hanging upside down for almost three days.

The 35-year-old magician was hoisted by his heels over the Wollmann ice rink in New York on Monday.

He intends to remain there until late Wednesday, despite doctors' concern about the effect of the stress on his internal organs and blood circulation.

Blaine said he was "doing all right" on Monday, though he did admit his head felt like it was "about to explode".

His previous stunts include spending 72 hours encased in ice, seven days underwater and 44 days without food in a glass box.

Blaine is suspended from a four-storey high metal frame, though he can be lowered to speak to fans face to face.

Catheter

He is also able to free one leg, using its weight to raise his head to a horizontal position.

For two nights and three days he will neither eat or sleep, taking liquid through a straw and passing water through a catheter.

Blaine demonstrating how he would hang upside-down last week

Asked to compare this current spectacle with his earlier endeavours, the Brooklyn-born performer said this was "the most difficult for sure".

"The others you could get into them soon after the start," he told an interviewer. "But this one is tough from the get-go."

Blaine said he would use "sheer willpower" to complete the challenge - inspired in part by his hero, the legendary escapologist Harry HoudiniHarry Houdini.

He has said he liked to test his endurance "because it gives me a different perspective, for a short duration".