never heard of this but my friends were trying to pass out by hyperventilating thinking it would feel really cool, fortunately they only got light headed.
yup i had riends doing that when i was in high school,they would also press their thumbs on each others arteries in the nech untill they passed out
several ended up with stitches from collapsing and smacking thier heads
for some the smack to the head worked,cause they didnt so it again.some did
me i got my rushes from other means not mentionable here