A schoolboy is in a coma after he collapsed while attempting a bizarre new craze called 'thumb blowing'.
Sam Thomas, 12, copied an internet video instructing youngsters how to use the dangerous fainting game to get high.
The craze sees kids put their thumbs in their mouth, squeeze their chests and repeatedly blow through their fingers until they hyperventilate.
But Sam, of Newquay, Cornwall, blacked out while trying the 'thumb blowing' stunt with friends. He managed to get back to his feet and staggered to school but soon felt pins and needles and started to feel faint.
Sam's horrified parents Celia and Robert Thomas raced to the school to find their little boy's body 'shutting down'.
He was rushed to hospital where doctors feared he would suffer brain damage and were forced to put Sam in medically-induced coma while they ran further tests.
Sam was in the coma for 36 hours and has since recovered – but his family have issued a warning against 'thumb blowing'.
Robert, 47, told his local news agency: "I picked him up and he had no blue in his eyes, they were all black.
"There was nothing I could do to help him. He didn't know who I was, he couldn't talk, couldn't walk.
"We went to the doctors and they called an ambulance. They needed to know more about what happened as they were really worried."
His anxious family sat helplessly at his bedside as medics waited to see if the youngster had suffered permanent brain damage.
Celia, 43, said: "He needed neurological rest but they couldn't assure us he was going to be OK. We didn't know if he was going to wake up knowing us. It was a long 36 hours.
"The next day they came to wake him but he took a while to come round and he didn't talk for a while.
"We had never heard of this thumb blowing craze before, that's also what was really worrying. We were in disbelief that this could be so dangerous.
"It's caused death before and many more children have suffered brain damage. Children at that age don't understand things like this, there's no fear or danger.
"It's really important children understand the risks and we'd encourage parents to talk to their children about this.
"I'm not angry or cross, because children are children. But no one wants to go though the 36 hours we did."
Sam is slowly recovering from his ordeal but has had to cut down on sports and swimming. His parents are desperate to warn other youngsters of the perils of copying dangerous fainting games they see on the web.
Various versions of the stunt are listed online – known by a variety of names from the funky chicken to the space monkey.
They involve hyperventilating or squeezing the carotid artery in the neck for a few seconds – achieving a momentary high.
Sam's school Newquay Tretherras Academy said it had acted 'instantly' to warn children not to try the dangerous stunt.