Traveler checks are not easily accepted in shops, restaurants, hostels, etc., however exchanging them is not a problem. A 7% commission fee will be charged at the airport, 6% to 9% at banks in the city, while only a 2% will be charged in exchanging bureaus.   Medical Insurance Many credit cards provide a medical insurance when you are abroad, however if yours doesn't or don't have your own health insurance you may get emergency and health coverage of any of the insurance companies operating in Lima. The main ones are AIG Assist (242-9393), Assist Card (446-0710) and Pan American Assistance (446-4947).