Upon unlocking from The Lore Store, traveling healers can randomly spawn throughout the world. If a character enters a hex with a travelling healer, they can make a vitality check for free to recover some Health (or no health if they fail horribly), and then the healer will go away. Rolling a Full Heal will also restore that character's Focus.
Traveling Healers are a welcome sight for injured characters who are low on Health-restoring items and gold, since they don't cost gold and are risk free.