For the hottest, you should wear pure cotton and the clothes should be loose-fitting. Light-colored clothes reflect rather than absorb light. Watch how the natives dress. If they carry an umbrella you can expect rain. In cold areas take long johns, a sweater, and wool ski pants.
Wool socks are best.
Wear a windbreaker and long-sleeve shirts. Wear a wool cap that extends down over your ears and wear gloves. Consider the wind-chill factor and altitude as the wind combined with cold makes the body feel it is much colder. Limit the amount of clothing you pack, but make sure it is adequate for the climate. To reduce the risk of STD's, travelers should avoid anonymous partners, prostitutes, and other persons who have multiple sex partners.