The setting of the story is the kitchen of the Olson house in the mid- to late-thirties.
Their Olson’s little girl Matilda is sick, so they call a doctor. The girl is in the kitchen because that is the warmest place in the house. This indicates that the story takes place a long time ago, before there was central heat. The doctor’s visit only costs three dollars, but that is a lot to the family. The story was published in 1938, so that fits.
They were new patients to me, all I had was the name, Olson. Please come down as soon as you can, my daughter is very sick.
An important part of the story is the presence of diphtheria, a dangerous respiratory bacterial disease, in the child’s school. Without the diphtheria and the poverty, the story would likely have been very different. It was the danger of the situation that caused the parents to allow the doctor to be so forceful with their child that he actually caused bleeding in her mouth. The fact that the doctor was getting pleasure from hurting the little girl aside, the parents were much more worried that she was sick.
The setting is also important because the fact that the child is hiding the diphtheria is likely due to the barbaric nature of the procedure, from examining her throat to removing the membrane on her tonsils.