To be cool I like to eat no bread and way less grain.
I eat more cooling foods. Some examples are watermelon, grapes, pears, strawberries, mint and cilantro.
another thing I like to do is wear a cotton or linen scarf and keep it damp. I keep my hair wet and when it is really hot I get my clothes wet and work in soaking wet clothes. It is kind of cold and uncomfortable to be dripping wet but it is nice and cool as they dry.
I traveled on the Indian reservation in summer and everyone has an arbor outside their house where they sit and enjoy life. It is just 6 or 8 upright poles with more poles tying them together at the top to make a platform up at about 8 ft. They pile green branches on the platform so they have a large shady area underneath. It is really cooling under there. For large events they just make it longer. I went to the Sun Dance and there were two big arbors, each over 100 ft long. The shade they made was about 15 ft wide, ample width for tables and chairs. When I went a few steps away from the arbor it was it was baking hot. All those days were at or over 100 degrees.
The best ever is walking in the hot sun at Wheaton Labs and stepping into cooper cabin!