Not only can I not continue eating after finding a hair in my food (automatic gag reflex as has been mentioned upthread by someone else), I am constitutionally unable to return to the establishment where the infraction occurred--ever.
And on top of that, if I see a chef or cook without headgear leaning over the food, I assume something from their noggin is going to land on my plate. This doesn't prevent me from eating, but I get a bad feeling about it in the pit of my stomach and have trouble enjoying the meal.
If I see a headgear-less food preparer touch their hair, I am equally freaked out.
The glove bit is horrible. I have seen people make sandwiches and then make change in them.
I have seen gloved fingers go into eyeballs to remove eye crust and that eye pus stuff.
I have seen staff bring water to the table by holding my glass with a crab-like grip at the rim.
This morning, I was given an empty coffee cup (where the coffee is self-serve) by a cashier who had her thumb on the outside of the rim and her four fingers down inside the cup.
Like everybody, I have seen how America goes to the bathroom, with most people not washing their hands, which is why I am so easily grossed out by all of this.
See, I'm an idea man, Chuck. I got ideas coming at me all day. Hey, I got it! Take LIVE tuna fish and FEED 'em mayonnaise!
-Michael Keaton's character in Night Shift