Hot food is always OK. I eat off of grills or trucks in Mexico when I go there, and I’ve never had a problem. The food has to be hot and just cooked and served in paper or on a tray.
Also, spices (curry, chile, lime juice and even salt) are very present in instant food - that is, food truck food - and these are big bacteria killers.
NYC is fine...just don’t eat the hot dogs in the tepid grey water...
I take the same approach when eating at street vendors - especially outside the U.S. Freshly cooked hot food, served on paper or disposable plates and silverware if at all possible (just in case the dishwasher didn’t do his job, or the local wash water isn’t all that safe).
Mr. Mercat and I call them street grunts. Watch the food being cooked. We hosted a small festival at our farm last year with a food truck. It was great. Rent a portapotty and contract with a food truck. Instant party.