WARREN, N.J. -- More than 70 percent of Americans surveyed said their greatest concern when traveling is suffering a medical emergency (e.g., broken bones, heart attack, other sudden or serious injury or illness), according to a nationwide survey sponsored by the Chubb Group of Insurance Companies.

The survey -- conducted by Impulse Research of Los Angeles -- found that the concern regarding a medical emergency (73.5 percent) was more than double the fear of being mugged (30.7 percent) and three times the fear of being injured in a terrorist attack (23.4 percent).

A majority of those surveyed -- nearly 60 percent -- said they take medical precautions before traveling abroad, including vaccinations and packing antibiotics or other medications.

The fear of medical emergencies may be valid when you take into account that many Americans enjoy adventurous vacations.

The survey found that while on vacation, 26 percent of people ski, almost 14 percent go mountain climbing, and nearly 20 percent participate in what they described as "other potentially dangerous activities."