Polish Chlodnik Litewski (Cold Beet Soup, the relict of Polish-Lithuanian Commonwealth) is probably the best solution for the current heat. This is a kind of cold soup made from sour whole milk with all the butterfat intact or yogurt enriched with beets and beet greens, crunchy raw radishes, cucumbers, dill, chives and small amount of garlic. It is served with hard-boiled egg. 

Chaladnik! That's how it's cooked. :)

(Халаднiк, Šaltibarščiai)