Chicken wings and cold cut sandwiches are a good choice.  They're portable and will keep well in the hot sun, but they're also familiar and easy to prepare.
assitant
You can easily make sandwiches using pita bread.
assistant
Which foods should I bring for a picnic?
user
What does “picnic” mean in this context?
assistant
A picnic is like a meal outdoors in a scenic place.
user
You might want to have a hot and cold meal that includes chicken wings, sandwiches, and hot dogs.
assistant
Yeah I'll probably just have some kind of sandwiches and a few other things. Do you have any specific ideas?
user