914Driver said:
Well, that's one way to clear grinder dust out of your sinuses.
Trivia: breathing pure CO2 can cause your heart to stop as soon as the blood from your lungs reaches your heart, per a doctor who used this to test resuscitation techniques on lab animals. (You gotta stop the heart before you can restart it...) Fortunately for humans, breathing air higher than about 5% CO2 feels like you are asphyxiating even if the rest is pure oxygen, so it is (probably) really difficult to do this even accidentally.
I bet her sinuses burned for a long time after that.
