The Summer Nights — Jean Dunbar

Sister Philippa Morgan was inclined to build up a well of resistance when other people praised someone to the skies -- so she was not favorably disposed towards Colin Fletcher long before she had actually met him. He was clever, good-looking, charming -- but Philippa was deeply suspicious of him.

Then Colin was brought dangerously injured into her ward of the small South African hospital, and Philippa discovered that not only was he everything everyone had said he was, but she herself was by no means immune to his attractions.