Street car into domestic car

This is Captain Daisy. Earlier this November he started coming to our balcony for food, every single day without fail. I've grown attached to him, I give him food, warmth, shelter. But he's very sick :( he has a cold and constantly coughs and sneezes. That's why I added a handkerchief to his neck (the handkerchief looks like a cape and it has daisies on it, that's why I call him Captain Daisy <33) and wrapped him in a towel. He wants to come in but I can't let him inside- he's untreated and my mom has an allergy. Any tips on how to help him with his cold?