Popsicles!
When it's really hot, I don't have much of an appetite and am happy to eat fresh fruits and vegetables - cut up or not, in smoothies, salads and ....yes....popsicles!
Edited to add that I remember visiting Venezuela for a scientific meeting some years ago. It was very warm and humid and I believe I subsisted on the hotel's platos de frutas, three meals/day for most of the week!