Raw shellfish is particularly dangerous to persons who have liver disease or compromised immune systems. Avoid tap water, fountain drinks, and ice cubes. If you visit an area where there is risk for malaria, take your malaria prevention medication before, during, and after travel, as directed. To prevent fungal and parasitic infections, keep feet clean and dry, and do not go barefoot. Don't swim in fresh water.
Salt water is usually safer.
Iodine tablets and portable water filters to purify water if bottled water is not available. See above for more detailed information about water filters. Sun block, sunglasses, hat. The risk of motor vehicle-related death is generally many times higher in developing countries than in the United States. Defensive driving is an important preventive measure.