Hot dry regions like Pakistan and northern India have pleasant weather from October to March, with the winter months cool enough for light woolens. A U.S. passport is required for travel to all countries in the region. Most South Asian countries also require entry visas. Travel to certain areas of many South Asian countries is restricted and special permits may be required for these areas in addition to an entry visa. Prospective travelers should contact the embassy or consulate of the country they plan to visit for specific information.
Yellow fever is found in some African and Latin American countries.
If you plan to travel from Africa or Latin America directly to South Asia, check with the embassy of the South Asian country where you are going to see if a yellow-fever certificate is required. If the certificate is required and you do not have it, you will be refused entry unless you are inoculated and kept in quarantine for up to 6 days. Drug prophylaxis against malaria may also be necessary. Trekkers and mountain climbers, in particular, should take precautions to avoid frostbite, hypothermia, and altitude sickness. The latter two can be fatal if not detected in time.