Good job you never told us then!, specialy as we don't know where you live!...,
Wait a mo'!... 
You could probably make a few bucks if you knocked up a few of these, even if you did post the schematic, there's always peple not wanting/can't solder them up themselves. I know a temp controled fan setup would be the Bogs Dollox, specialy a 'controlable' one
. I'd like to see a hardware/curcuit made up for shutting down a PC from a flowsensor(connection made WITH flow)
and an indipendant thermistor to be placed next to CPU die or drilled into block, that monitors/displays the temp as well on a LCD screen(very small one), an 'all in one' shutdown package!
...