Let me see if I have this right:
For the good of the race and by your own admission you deem yourself better off dead, and you think of an especially entertaining way of blowing out your own candle? Ah, for the brave this could be choice!
"If turned on how long before his head exploded?"
I don't know about a human head, but once I did try to heat a cold hard-boiled egg (in shell) in the microwave. It did indeed explode (very loudly, too) after approximately 45 seconds. I spent the next 30 minutes cleaning up the mess - thankfully my wife was not at home at the time!