Instant gratification / Jill Shalvis.

Enhanced descriptions from Syndetics:

Wishful, California, is 3000 miles from Dr. Emma Sinclair's last job in a New York City ER. It may as well be another galaxy. Here, running her father's clinic for a summer, Emma treats bee stings, stomach flu, and the occasional pet cat. Plus, she has to contend with patients like Stone Wilder: gorgeous, laid-back, and irritating beyond belief. The man laughs at her. A lot. And Emma loathes him. All except that tiny part of her that wants to throw him on her examining table and break every doctor-patient rule in the book. When Stones tries to help Emma learn to loosen up a bit, he pictures white-water rafting or scenic mountain hikes. Not a mind-blowing affair that shakes them both to the core. Emma's sure she has no place in a town like Wishful, but Stone knows different. Emma belongs here - in this town, in his life. An convincing this strong-minded, stubborn, sexy woman of that fact will be a challenge no Wilder man could resist.