If you don't already have a turtleneck, go buy one. Now. Hell, even if you own a few, you should consider a one more -- maybe in super thin merino wool or cashmere (it'll take up less room in your suitcase).
Are you of the mindset that your clothing color choices should go with or match your hair color? If so, you are not alone. I hear this all the time and most often I hear this from people who have chosen to go gray.
Once upon a time, François Pasquier decided to throw a dinner party for his friends in Paris after having spent some years abroad. So many people responded that he asked them to congregate at the Bois de Boulogne dressed all in white so they could more easily locate one another.