After working hard for your vacation and looking forward to it for so long, what happens when you've purchased the least expensive non-refundable tickets and you have an unforeseen emergency that prevents you from making your trip? Unless you have purchased ticket-protector insurance, you're probably stuck. Continental, Northwest and America West airlines as well as several travel web sites offer such insurance.

Now, you may still be stuck, depending on the particular policy and the situation that prevented you from making your flight. Travel expert and author, Ed Perkins, calls ticket-protector insurance a "lite" version of trip-cancellation and trip-interruption insurance. Perkins says, "Instead of buying insurance that covers all your bases, like your hotel, car rental or most anything else, you are solely protecting your flight."

For years, several online travel companies have offered ticket-protector insurance. For about 4% of your ticket price you can be covered up to $3,000. However, before you purchase this insurance, you need to know exactly what is covered and what is not.

It is essential to understand exactly what the covered reasons are, as it could mean the difference between receiving a full refund and having to absorb the cost yourself. Covered reasons typically include medical emergencies, car accidents, terrorist attacks, airline delays or cancellations, natural disasters, death of traveler or family member, adverse weather, airline strikes and jury duty. Be careful, though, as those reasons may have narrower definitions than you would expect.

As an example, a sudden heart attack or debilitating injury would be covered. However, an existing condition such as epilepsy would not be covered even if you have a seizure two days before departure which prevents you from traveling. That condition is already being treated and therefore would not be covered under your ticket-protector insurance.

Adverse weather conditions do not include conditions that are "expected". For example, if you are traveling to a hurricane-prone area and a Category 4 hurricane is predicted to hit your destination days before your arrival, you will not receive a refund unless the airline cancels the flight or the airport is closed.

While labor strikes are covered reasons, you already have some protection on that front. There is a law requiring airlines to honor competitors' tickets in the event of a strike or shutdown. However, this law only applies in the United States. It does not cover international airports.

Critics of ticket-protector insurance argue that the coverage is too limited because unforeseen situations are very often not covered. If a person truly has a non-refundable, non-reusable ticket, the insurance may come in handy. However, no one knows their circumstances ahead of time and if there is a problem with the coverage, the insurance company usually wins.

Ticket-protector insurance should only be purchased under limited circumstances say consumer advisers. Airlines are sometimes criticized for prohibiting refunds and then selling insurance to provide those refunds. The airlines respond that providing the insurance gives travelers more choice.

So, is a traveler better off with ticket-protector insurance or more comprehensive travel insurance? While ticket-protector insurance covers only the flight, travel insurance generally covers all aspects of your trip. Chances are that whatever causes a person to miss their flight is also going to cause them to miss their whole trip, or at least necessitate changes across the board, i.e. car rental, hotel reservations, entertainment tickets, etc. A consumer must weigh all factors involved in making the decision on which insurance to purchase, if any.