Add chocolate chips, caramels, milk, heavy cream, and vanilla to the slow cooker. Cover and cook on low for 2 hours.
Stir the hot chocolate. If the chocolate chips or caramels are not completely melted, cover and allow to cook for 20-30 minutes longer. When ready to serve, stir in the sea salt. Serve hot with whipped cream and additional caramel sauce if desired.
Chocolate: milk chocolate chips will yield a much richer flavor - I like to use a combination of both!