Fevers and epidemics
× The herbalist could also have a new function, which is to cure sicknesses that are brought into the town by traveling merchants, or when a hearthling catches a cold during winter
I had this thought while playing Banished the other day, and I thought it could also work in Stonehearth.
The fevers not necessarily have to be lethal. A sickness could weaken a hearthling by having him/her move slower, require more sleep, craft and work slower, consume more food, deal less damage in combat, etc. They would generally last for a few days, or longer for rarer fevers, unless treated by a herbalist.
There could also be an option to disable this if the player doesn’t want to face them in game.