What should I be aware of when eating street food?

A couple of perhaps less obvious tips:

1. Wash/sanitise your hands before every meal – in many countries you can get quite dirty quite quickly, especially when visiting highly trafficked areas like tourist hotspots.

2. Trust your senses of smell and taste – if something tastes bad, spit it out; that is unless you’re trying something that tastes ‘bad’ by design (I’m looking at you, stinky tofu). Most of us have highly developed food safety sensors built into our faces – pay attention to them.

Street food should be assumed to be unsafe for human consumption unless you have evidence that it is safe. Before travelling to a country, you should do research about the quality of foods in restaurants, because even in restaurants there can be problems. And it’s not that unsafe foods will make you acutely ill, because those problems will get filtered out automatically, as few people will continue to eat in restaurants where they can’t make sure people don’t get health problems in the hours and days after eating.

For example, the situation in China used to be quite bad, see here. If you eat these oils, you usually don’t get ill on short time scales. But you’re then risk of getting health problems after eating foods prepared in these oils regularly over a long period of time.

In my personal experience there is very little correlation between "visible food safety measures" and getting sick. I’ve been 40+ countries have eaten a lot of local food and had plenty of "mystery meat on a stick" in places where refrigeration isn’t a thing.

The only time I got food poisoning on the road was in un upscale western hotel in China, not street food. The worst food poisoning I ever had (almost died) I got at the food court of the most expensive mall in Cambridge, MA, USA.

Americans seem to be more paranoid about food safety than most other countries. In the US, meat that’s been outside the correct temperature zone for a few minutes is considered highly dangerous, in Germany they eat raw ground pork on a roll by the metric ton at every street corner. No one gets sick.

One tip that has probably merit: avoid raw foods (salads, raw vegetables) that’s been washed in countries where the tap water is really bad. Street food is generally fine.

Busy places where you can see the kitchen and goings-on (such as freshly prepared, and reasonable treatment of raw meat) and seem to be safest. And limited menus. So a crowded (with locals, especially) street stand where they have one or two wildly popular dishes would be pretty safe. For example, the cowgirl vendor in Chiang Mai.

Worst would be some place that is deserted, kitchen out of sight and appears to cater to non-locals such as bus tours, and has a suspiciously lengthy menu.

That said, certain countries just seem to be safer than others. China, HK, Singapore are much safer than Vietnam, for example, and I seem to get sick almost every time I go far south of the US border (Mexico City excepted). Part of it is sanitary standards, but maybe also the locals have built up more resistance.

Reviews and ratings are always good but it is possible to get sick pretty much anywhere, even in a well rated restaurant in developed country. Some people just have more sensitive digestive systems. While I also used to eat pretty much anywhere and trying most things, my body cannot handle this anymore and I get violently ill from my stomach very easily now.

The best way to reduce chances of getting sick is to go when the throughput is high, so a popular place at a popular time. This happens simply because ingredients have to be replenished more frequently, so they will be fresher when you get them. With street food, there is much less storage space to keep food at a low temperature to prevent bacteria growth, so a place has to restock often, than food will not have to stay out for long.

Exercise caution according to the cleanliness of the area. There are place with much stricter controls and sanitary rules than others. When you see cleaning crews passing often and surfaces clean, food will be more sanitary as well.

The availability of drinkable water in the area is also a strong indicator. Numerous ingredients have to be washed before preparation and so, if the local water is not drinkable, or not drinkable to you, then it will be more likely to contaminate food. One common rule is to avoid fruits and vegetables that cannot be peeled. This rule saved me many times.

Cooking temperature for meat and fish is crucial which is the reason why there are national guidelines in numerous countries. With street food, you can often see the cooking method and learn which is most likely to cook meat sufficiently. Low meat temperature has gotten me seriously sick in many countries, including the US and Canada. Some street food vendors will have cooked early during the day or even in the morning and basically warm it up at the time of serving. This is very bad in my experience. It is better when they start with raw meat and fully cook it right before serving but do pay attention to where they take it from before cooking.

When ordering, consider which items are selling well. If you buy the one off exotic item that rarely sells, you may get sick more easily. This is one lesson I learned the hard way! Consider the risk too. There will be simply times when getting sick is even worse, either because of local healthcare or because of your plans.