"The scarlet letter had endowed her with a new sense." Explain this, using textual evidence to show what this means?

[page 93] The vulgar, who, in those dreary old times, were always contributing a grotesque horror to what interested their imaginations, had a story about the scarlet letter which we might readily work up into a terrific legend. They averred, that the symbol was not mere scarlet cloth, tinged in an earthly dye-pot, but was red-hot with infernal fire, and could be seen glowing all alight, whenever Hester Prynne walked abroad in the night-time. And we must needs say, it seared Hester's bosom so deeply, that perhaps there was more truth in the rumor than our modern incredulity may be inclined to admit.