Spicy chickpea and cumin salad, tabbouleh, carrot and avocado salad... How long will you be without refrigeration?
Those are the 3 dishes I usually take with me on long plane trips, but if you had some fridge time, you could also add cheese, eggs, and meat to that. I don't eat meat so I am not sure about all your options there, but you could definitely bring some beef or turkey jerky along for a while.
You could also bring along a quinoa or rice-based dish with vegetables.

There's the old standby, peanut butter and jelly. Or my personal favorite, peanut butter and chocolate (nutella or frosting)

There are some boxed milks out there that don't require refrigeration - Organic Valley, I think? They taste pretty good.

Nuts, apples, apricots, peaches, either fresh or in a trail mix bag are good for snacks.

And jerky, as noted above, but I only use that for road trips, myself.

What I do at work is pack what I want to eat and have an ice pack in my bag - DIY refrigeration.

Besides recipes, i offer the example of traveling to a very warm Austin with all sorts of things on ice in a cooler, but mainly a bowtie pasta salad. All hotels will have ice available and we happily ate that pasta salad for at least three days.

Some sandwiches are better for being able to sit, meld and marinate as well. There was this one gigantic sandwich being passed to us by strangers at Red Rocks that was made from a huge round flat loaf that had been hollowed out and sliced in half, stuffed with turkey, cheese and lord knows what else but it was an amazing sandwich, not slightly in part because of the setting, situation and camaraderie.

Also, there are lots of things in those sealed tetra packs.

Doing the cooler thing was far easier by using bags and containers of ice to easily and tidily deal with changing it.

Cheese needn't be refrigerated (I like fig jam & sharp cheddar sandwiches, yum!). An unpeeled boiled egg will be fine at room temperature for a couple hours. So will a pasta salad, for that matter, even if it has veggies in it.

If you don't like room temperature food (which I can understand), I suggest blue-ice lunch paks or make your own by filling up a heavy-duty zip bag with crushed ice and a little water and refreezing it or by filling (not completely full) a hot water bottle and freezing it.

I never refrigerate my lunches and I haven't died yet. we used to eat bologna & cheese in grade school that'd been heating up in a locker in non-A/C schools as kids, back before people cared about food safety. AND WE LIKED IT THAT WAY. ahem...

caveat: I loathe mayonnaise, so I never have that danger consideration.

Points to ponder:

- Yoghurt is fine at room temp for at least a day, often longer. yanno, cos things like cheese & yoghurt are technically already "rotten".

- the "danger zone" for left-out cold cuts kicks in somewhere around 4 hours, longer if they've got preservatives in.

- Eggs aren't even refrigerated in most civilised areas outside the US.

- fruit is always a safe bet

- I often just freeze a (plastic) water bottle overnight full of whatever fluid I desire (not milk because I loathe that, too) and then stash it wrapped in a towel next to my lunch (so it doesnt sweat on my clothing).

honestly in any air conditioned environment you should be fine.