Finally I have a few minutes worth of time where I have nothing else to do but argue with the lot of you.
In short:
People are stupid. I know many 18 year olds who have no idea exactly how dangerous electricity is (even if you survive the initial shock, there is a very good chance you will die later as a result of rattling your CNS or heart's rhythm). I doubt any of you do, either.
The fact of the matter is that voltage has no significance when you are dumb enough to run the current through your chest. When you do that, there is a very, very good chance that some of that current will pass through your heart. Your heart, as you hopefully already know, is controlled by electric shocks. When our natural rhythm of shocks is disturbed, it causes our hearts to either be arrythmic (much like a bad street performer) or stop entirely. Neither of which are good options if you like to keep oxygen flowing to your very oxygen-greedy brain and maintain its functions. Electricity is also quite fond of travelling through your central nervous system, moving through your axons - and this can often mess with your respiratory system.
There is no way in Hell that this student knew what he was doing when he did it. No person with any knowledge of electricity would ever run a current through his own chest, regardless of potential economical gains.
The teacher, however, should not be held accountable for a person completely lacking in regard for his own personal safety. Any person who wakes up in the morning, showers, gets dressed, has breakfast, and enters his science class thinking "Here's an idea! Today I'll run an electrical current through one nipple and out the other!" is not a person who should reproduce, let alone sue an educational system.