His mild frown is the only show that he's at all concerned. He keeps his tone calm and professional.

"I'd like you both to come straight to the hospital with minimal contact with anyone else. I'll meet you at the front."

Because he doesn't want either of them in contact with anyone else, either. As a Guardian, and the Guardian of Healing no less, he knows he's immune to all forms of illnesses, but that doesn't mean anyone else is.