Is Whim Hof Breathing Dangerous?

[SQAAD]

@undeather 

16 hours ago, undeather said:

No, that would not be dangerous. Dont' worry about minor stuff like that.

Ahahahaha it's hard not to worry about every single detail. My  brain is very detail oriented. That's  a gift and a curse at the same time. Thank you for you responses. Because of you now i practice more breathwork and i feel better throughout the day. 

One last thing: What causes the feelings of euphoria that breathwork can produce? I think you gave some explanation to this but still i don't understand.