1. Is there a crowd? Just like at home, go where the locals go, as they obviously know where to find the good stuff. But high volume also means that food is being prepared fresh, rather than sitting around attracting flies and turning into something useful for waging biological warfare.

2. Are basic hygiene practices being implemented by the vendor(s)? In Mexico, I've frequently observed street vendors slipping clean plastic bags over plates. With every order, a new bag is used, then discarded at the end of the meal. It's an eco-nightmare, but it's a lot more sanitary than dunking a plate in a bucket of dingy water doubling as a petri dish. Also bear in mind that in many parts of the world, the left hand performs double-duty as toilet paper. I can't say it enough: Look at the sanitation practices before ordering.

You'll often find co-workers whose sole responsibility is to handle money, to avoid cross-contaminating food (this isn't always the case, however, so sometimes you'll just have to--literally--suck it up). Once, when I accidentally handed my money to the wrong guy, he turned his hand upside-down to avoid contact with my filthy coins.

3. Is the stand or cart clean and well-maintained? Is hot food kept hot or cooked to order, and is cold food cold? Is purified water or ice used for beverages and frozen treats?

4. Are the ingredients fresh? If you've got eyes, a nose, and some tastebuds, you can figure this out for yourself. I look at the condiments and garnishes to determine if I want to eat at a given stand or cart. If I see crusty bowls of salsa, dessicated limes, slimy herbs, or flies congregated on any raw foods I might potentially eat, I'm out of there.

Stick to local specialties. One of the greatest joys of travel is eating regional ingredients or dishes. It also stands to reason that ordering seafood in an inland desert is a calculated risk. Raw protein products (egg, meat, poultry, fish, fresh cheeses) in general are to be avoided in the Third World. What about dishes like ceviche, where the acid in the citrus juice denatures (breaks down proteins, killing some potential pathogens in the process) the fish? It's still risky, because technically it's an uncooked food, and only application of heat over 145 degrees can totally annihilate anything potentially deadly lurking in fish. Again, use good judgment based on freshness of ingredients and basic sanitation, but remember that you can't eliminate all risk.

If you're in a coastal region, it pays to do a bit of homework on the cleanliness of the local fresh and ocean water supplies; algae blooms or cholera outbreaks will be widely reported. Try to avoid eating raw river fish or seafood, or river fish/seafood from just offshore; remember that many developing island nations and coastal regions use high tide as their toilet. If you're eating pork in the Third World, always make sure it's well-cooked. While trichinosis has effectively been eradicated from our domestic industrial pork supply, the disease is prevalent in other parts of the world. And not to get too graphic, but you'll often find pigs in rural parts of the developing world lurking around latrines, searching for a snack.

Fresh ingredients don't necessarily mean great food, but it helps. Delicious street food is ulimately a reflection of the loving care that goes into its preparation. Are the carnitas slightly crispy on the outside, with an interior succulent with greasy goodness? Is the masa in the tamales moist, with a sweet, earthy corn flavor? Are the noodles slightly toothsome, the herbs fresh and bright-tasting, the broth fragrant and piping hot? These things matter.


5. Use hand sanitizer before eating, take probiotics with live active cultures prophylactically, and pack a broad-spectrum gastrointestinal antibiotic and Imodium, just in case. I'm just sayin'.

For more information on food safety, go to this page on the USDA website.