If symptoms develop, Diamox can help mild cases. For more severe cases, descend to lower altitudes ASAP and seek medical attention. None are generally required though some recommend vaccinations against yellow fever and typhoid. Malarial prophylactics are recommended when visiting the Amazon. Potable water is not universal in Ecuador, so only drink bottled or boiled water which is, in general, safe.
Valid passports are all that is needed to enter Ecuador as a tourist.
Tourists may remain in Ecuador for up to 90 days in any given 365-day period without a visa. Tourist visas are issued in-flight in the form of your arrival card. Make a photocopy of your passport. It will help expedite the replacement process should you lose yours. For full details on all types of visas, including work visas, we refer you to the Website of the Consular General of Ecuador .