How do you know when a Smurf is suffocating?

Question

How do you know when a Smurf is suffocating?

Answer 1

If after having a very long one-sided conversation, you realize that said Smurf is not only no longer communicative, but also dead. This may involve twitching of limbs, and then a sudden stop of all actions. I suppose that their human-like qualities would stop them from being under water for extended periods of time. If a smurf is under water a significantly longer time than you could ever be, then there is a good chance he/she/it is suffocating, or at least not breathing. Good luck on your quest!  

Answer 2

when his head blows up

Answer 3

When it turns dark purple..... I read this in a fun fact sheet somewhere....

Answer 4

His lips turn white and his fingertips!