<< I realize that this doesn't have much to do with the topic at hand, but I just wanted to mention something:
Did you know that it's physically impossible to die from voluntary stop of breathing? Eventually (in two minute or so) you lose consciousness and your body begins breathing again. : >>
Not if tell them to put a plastic bag over their head to make sure no CO2 gets out.
Most of the people I talk to are stupid enough to do it, and I mostly deal with field techs now.