Desert Doctor, Secret Sheikh – Harlequin Medical Romance #339 Mar 08

Dr. Jenny Stapleton has devoted herself to those in need around the globe.  When Dr. Kam Rahman shows up at the clinic she's set, she thinks he is only a doctor, but actually he is a sheikh.  By traveling anonymously he can learn his country's needs.  He is struck by Jen's passion for his people and he wants her as his queen.