Hot or cold water when cooking pasta?

Wow…so much fear. I guess growing up in NJ sorta makes me a little immune from the hot water is dangerous syndrome. I also wash my dishes in that hot water so trace materials are probably all over my dishes, my pans are metal, I see my plastic spatulas have a few dings and I probably have eaten a few egg shells.

I start with hot water, add salt, bring to a boil and cook to doneness.

I have a question for all the posters wanted to save a smidgen of energy, why do you not only eat capellini since it takes a fraction of the time as thicker pastas? Seems a bit counter-intuitive if penne and ziti are on your rotation.