It's well-known among low budget international travelers (and those that go well off the beaten path) that when s--t gets sketchy you just eat what's deep-fried. Hot enough to fry is hot enough to sterilize. Mickey D is not high culture but it's probably safe wherever you find it.

Right - McDonalds has very specific corporate policies relating to food safety as well as a cleaning schedules, holding times, and the like. At least that's how it was when I worked at Popeyes, I assume that most fast food chains will be similar.