In summer's hottest weeks (or months) I keep a glass dish with a glass lid in the refrigerator filled with fresh, organic if possible non juicy vegetables that've been scrubbed, cut into bite size pieces, and sprinkled with a tiny bit of lemon or lime juice. I use lots of colours so that it looks apetizing - for ex., radishes, carrots, cucumbers, capsicum red and orange, celery, tiny salad turnips, and sometimes a few sliced olives or capers for a little salty extra bit.
I dip these into goat cheese, hummus, or peanut butter, or just eat them plain.
Also a big glass of whole milk with a few drops of vanilla makes a good dessert in summer.