The purpose of Travel insurance is to cover medical expenses, financial default of travel suppliers, and other losses incurred while traveling, either within one's own country, or internationally. Temporary travel insurance can usually be arranged at the time of the booking of a trip to cover exactly the duration of that trip, or a "multi-trip" policy can cover an unlimited number of trips within a set time frame. Coverage varies, and can be purchased to include higher risk items such as "winter sports".
Terrorism is excluded except for the Emergency Medical and other expenses section, Personal Accident section and Hijack section (where cover is provided as part of the policy). If the terrorist act involves a nuclear device or a chemical or biological agent, there is no cover at all.