Nurse

The Nurse is an NPC that will spawn once the following criteria have been met:
 * There is an empty house.
 * You have found and used a Crystal Heart.

The Nurse will heal your wounds, for a small price. Healing costs can range from a few copper to a few silver, depending on how much damage you've taken. It costs 1.33 copper per hitpoint that will be restored, rounded to the nearest whole number (ex. 75 copper for 100 hitpoints).