Also, if you have been drinking heavily, do NOT drive the next morning.
My brother-in-law was a heavy drinker, but never drank and drove. He always left the car at home. One Sunday morning, after partying the night before, he went to pick up his kids from a sleepover. He had an accident, a woman died, and he went to jail. He was still buzzed from the night before - it takes time for the alcohol to be processed by your body. He was 'lucky' that he ended up with several years house arrest (first-time offender), BUT he has to live with the guilt for the rest of his life. He is a broken man, and two children lost their mother.
Be careful out there! Have a safe holiday season.