Shiva cooled down but his mourning continued. He did not returned to Kailasha without Sati, instead he went for meditation in a cave of Himalaya.
In the mean time according to Vishnu's wish Sati rebirth as Gauri or Parvati, daughter of Giriraj (King of mountains) Himalaya and Menoka. As "parvat" is another term for "giri" or mountain she is also called "Parvati". When

Gauri attained her age of marriage Narada, worshipper of Vishnu, came to Himalayas' court. He according to Vishnu's instruction forecasted that Gauri would be a right match for Shiva. 

Delighted Himalaya requested Shiva to let his daughter worship him. Mahadeva allowed her worship. Gauri started her Tapashya or meditation for Shiva for three hundred years eating nothing but leaves of wood apple. But she failed to please him. She started the final phase of her rigorous meditation, Panchatapa, keeping

Sun right above her head and fire surrounding her. Days and months and years passed away when suddenly Shiva appeared in disguise to test her devotion. Her devotion won heart of Shiva. Heaven rejoiced in delight. The marriage was arranged and the lost lovers were united forever.
But still Shiva is afraid of loosing her and aware of any more insult to her beloved. You can find him piping from a corner or above the idol of Durga watching his wife and family in her fathers' abode.