What do the narrator and three other men do each day?

The American narrator and the three Italian soldiers from Milan go to the hospital each day for treatment on wounds from the war. After working with the machines, which the doctor swears will heal them, they go together to the Café Cova near the famous opera house La Scala in what the narrator labels the "communist quarter" of Milan. People in this part of the city scream insults at the soldiers because they are officers. Another boy, who lost part of his face and now wears a "black silk handkerchief," sometimes accompanies them. Presumably the men spend time in the café drinking and flirting with the girls. Obviously these girls are quite friendly to the soldiers, and the narrator notes that the "girls at the Cova were very patriotic, and I found that the most patriotic girls in Italy were the café girls."
While the three Italians are initially friendly to the narrator, their attitude changes after they learn the narrator basically received his medals because he was an American. It is understood that these men had actually won their medals for extreme bravery in the face of the enemy. This section of the story may be highly biographical, because Hemingway was wounded during the war while working on an ambulance crew. He was hit in the legs while handing out chocolate to Italian soldiers in the trenches. The narrator and the three Italians ultimately "drifted apart," although the narrator remains friends with the boy in the black scarf.