I was told by a certain "know it all" not to eat sushi on a rainy day or sushi prepared by a female chef. According to them, bacteria breeds easily on sushi on rainy days and women have warmer hands than men, therefore again bacteria.
Is there any truth in this or is this person full of b.s?
I call BS (and sexism) on that one. Bacteria breed easily on any surface that has a suitable growth medium and an adequate temperature. The rainy day myth may have originated in a time and place where humidity control and refrigeration were not widely available but these days I can't see how it would make a bit of difference (amazing that we here in soggy Seattle have not all dropped dead from eating food on rainy days). And as far as the warmer hands, I think physiologically, women tend to have colder hands due to somewhat lower peripheral circulation than men. Some say that women make better biscuits and pastries because their hands are colder. Go figure.
Mostly I think the women and sushi myth arose from a desire to keep women out of the high profile, high profit world of sushi and back in the low profile, lower profit world of the back of the house. My 2 cents.
Even if the mean hand temperature for the group of all women is greater than that for the group of all men, it doesn't mean that any given woman will have warmer hands than any given man. There would still be significant within-group variance. Therefore, even if warm hands foster bacteria, it is silly (and sexist) to refuse sushi prepared by a female chef because using sex as a proxy for hand temperature is both under and over inclusive.