In Colonial days, barkeeps would heat pokers in fireplaces and plunge them into rum-based drinks called flips. They had nothing, however, on Dave Arnold, the culinary science whiz at the French Culinary Institute and partner with David Chang in the new cocktail bar Booker and Dax. Lacking a fireplace, Arnold uses high-tech electric pokers of his own invention. So what do you get when you insert a 1,500-degree rod into a mixing glass of, say, rye, Campari, sweet vermouth, and Pernod? Foot-high flames for starters. Then something like you’ve never tasted before—a deliciously complex concoction full of toasty, bitter, caramelized flavors that will have you rooting for six more weeks of winter (207 Second Ave., at 13th St.).