There are three Illnesses in the game:
- food poisoning
If your worker is not feeling well, you'll notice green particles around them, and a new information will appear when you open their details window.
Apart from sending a worker to a Physician, the player may also send them to bed until they get better; or, alternatively, they will themselves take medicine if its available.
The medicine for a hangover is Lager, for food poisoning it's Medicine, and for cold - Herbs.