Hmmm. Maybe sliced watermelon? Chex mix? Smoked meat (flavored beef jerky)? Freshly-baked bread? I'm a man of simple tastes, so my apologies if none of that is fancy enough for you, but I was thinking picnicky-type foods.

I think of fruit salads as a cool dish, but there's no reason why they wouldn't work well warm. (Fruit compote, after all...)

Bugs in general would be a concern. In this case, it was - happily - not a problem. I'm not sure why bugs weren't a problem - just enough breeze off of the water we were next to?

Those screen things are mighty handy, but they hardly provide THAT much in the way of shade.

Roast beef and hard boiled eggs are both fine.
Tomatoes with salt
pickles!

After 6 hours? None unless you can keep the insects off. And anything meant to be cold certainly wouldn't taste very nice.

That chocolate article is just more proof of my argument that the Netherlands is a joke country.

(no offense intended to Netherlanders ... just being silly)

Just figured this is probably picnic food you're talking about. The Two Fat ladies did a fantastic picnic episode -- the recipes are probably on foodtv.com. Jamie Oliver did, too. One of the things the Fat Ladies did was a steak and mushroom sandwich -- seared steak and sauteed mushrooms in a hollowed-out loaf. No mayo, no threat. Also, layers of roasted veg (I like red and yellow paprikas, eggplant, and courgettes/zucchini with a little goat cheese. Layer and sprinkle lightly w/good olive oil and basalmic vinegar and herbs, put it in a loaf of VERY crusty bread -- heavy peasant loaves, rather than light baguette-y -- and wrap very tightly. You can also use fresh mozzarella. To reduce sogginess, you might lightly marinate the veg before roasting and omit the dressing after wards. A nice apple crisp/crumble will also sit out nicely. Tabouli is generally pretty tasty -- in fact, I think most mezze-type things will be both safe and tasty.

I would not agree with the boiled eggs, though. Safer than other eggy things, but still best not to leave out for too long, even at room temperature, unless they're pickled. For example web.extension.uiuc.edu/macombcenter/nutrition/egg%20safety.doc. Granted, I think sites like this generally err on the saide of over-safety, but 6 hours in the heat is not something I'd risk, myself. I'd probably go that long, or even a little longer, if I were camping or hiking in weather below 50 F, though.

Marinated veg salads, or cruciferous veg-based ones are better. Another option is Indian or Thai foods made to be served at room-temperature. THe spices have natural anti-bacterials, and the foods will taste much as they should.

I was also thinking of fresh fruits. A bowl of different kinds/colors of seedless grapes (white, red, purple) would still look/taste nice after a few hours of sun, & Saran Wrap over the top should keep all the creepy-crawlers out.

Kiwis would also be a good choice. Not something most folks have all that often, and even when warm a ripe kiwi tastes delicious on a hot day. Pineapple as well.

Some canned foods ought to do alright. Pitted Olives or fruit cocktail in a can. Doesn't need to be kept cool, and they can be kept in a bag & should be just fine (as well as being durable if somewhat banged about by other stuff).

Pecans or walnuts should also hold up well. If you brought a plastic bottle of honey, a few apples, & some nuts, you can make a tasty little salad. Leave the apples intact until right before serving. Peel & slice (a little Pampered Chef tool does this in seconds - http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=4457700225&category=20641 ) the apples, sprinkle the nuts & pour some honey on & presto, you are done!

If you were to bring UNRIPE fruit or vegetable, such as a pineapple or tomatoes, in (and this is important) a brown paper bag - to your sunny picnic, it would ripen during the day and be perfectly ready to eat after six hours in the sun. They would be quite delicious warm too.

Or try going to the picnic with all the food - sandwiches, pastas, meats, drinks - frozen solid. (Fresh greens wouldn't do too well). The frozen food would defrost and be ready to eat.

I should think that desert cuisines would offer plenty of ideas - couscous, dates, nuts.