Credit card help?
Several premium credit cards promise help in an emergency in a foreign country. Although the language in the card literature seems to promise a lot, however, what you really get is a referral, not any genuine financial assistance.
The fine print for the AmEx Platinum card, for example, says, "Whenever you travel, have peace of mind knowing that you have 24/7 medical, legal, financial, and other emergency assistance while traveling more than 100 miles from home. We can direct you to English-speaking medical and legal professionals and arrange for a transfer to a more appropriate medical facility, even if an air ambulance is required." Note that it says "arrange for," not "pay for." What you get is help in making arrangements; the cost of those arrangements goes right on your credit card bill (unless moving you is deemed "medically necessary"). As far as I know, other cards operate the same way.
Making the choice
The medical risks you face when traveling outside the U.S. are hard to quantify. Basically, the chances of facing a major medical problem are small—very small, for medevac—but the financial consequences of a serious event are potentially quite large. Once again, it's your call.
Fortunately, prices are not bad. As with all travel insurance, my suggestion is that you check with one or two of the online travel insurance agencies, enter your personal details, trip details, and the coverages you want, and select the least expensive policy that meets your needs. Some of the major agencies include 1Travelinsurance, InsureMyTrip.com, QuoteWright, Squaremouth, and Total Travel Insurance.