There are no vaccination requirements for entry to Chile, but Hepatitis A immunisation is recommended. All water should be treated as if contaminated; bottled water is available. Santiago is severely polluted and this could cause respiratory problems or eye irritations. Travellers visiting the Andes Mountains should be aware of altitude sickness, and if possible ascend slowly to allow the body to adjust. Health care in urban areas is adequate, but hospitals and clinics are extremely expensive and usually require payment in cash. Health insurance is strongly recommended.