Perhaps this myth started with the image of a Saint Bernard carrying a flask of brandy around his neck when rescuing people buried by snow in the French Alps. While alcoholic drinks create the sensation of warmth by making blood vessels dilate and stimulating nerve endings in the skin, this can actually make your body temperature fall. (Which isn’t good if you’ve just been pulled out of a snowbank.) Best to leave that glass of brandy for when you are safe and warm and relaxing by the fire inside the house!