The expression “to have one’s heart in one’s shoes” is no more than the current version of a very old saying that describes extreme fear.
An ancient humorist, wishing to imply that his heart sank lower with fear than another’s could, wrote, in the early fifteenth century, that his heart fell down into his toe.
Successively through the centuries, and depending somewhat upon the costume of the period, the heart has metaphorically sunk to one’s heel, to one’s hose, to one’s boots.
