The son is the inspector and wife's son, the mother-in-law's grandson, the uncle's great-nephew, and the niece's cousin.
The son will go sick without food for 1 day and will go sick without heat for 3 days. His sickness threshold is 4. Like everyone but the inspector, he gets cold, hungry, sick, very sick, and possibly dies.
He will make a drawing on day 19 if he is still alive to that point and has received the crayon set the day before his birthday, which is on day 18, making his birthday December 11th. The 'masterpiece' can be hung on the wall of the inspector's booth, an example of the naive art movement. If the drawing is on the wall on certain points in the game it can lead to ending 11.