No matter how many times you brief a passenger to keep his mitts off the pitot tube as they walk by the front of the helicopter....they will insist upon ignoring your request.
However, the first time you forget (on purpose or not ) and leave the Pitot Heat on....they will never touch it again (especially if they leave their finger prints behind in the form of shriveled up burnt skin!).
Of course 212Man will never admit doing that before....right?