You might want to consider going to the nearest lake or pool when the temperatures rise over 90 degrees, but if you do decide to brave the heat, make sure you drink plenty of water before hiking.
Wear white- or light-colored clothing made of a lightweight, breathable material so that sweat can evaporate.
Drink often. Adequate hydration helps your body’s cooling system keep your internal temperature in check. Keep your drinks as cool as possible, and add energy and nutrition to them with powdered sports mixes. The best indicator of proper fluid levels is urine output and color. Your urine should be "clear and copious". Dark urine means the body has concentrated the urine because it is low on fluids. If you develop cramps, you need to hydrate and take in some food containing potassium; i.e., bananas, apricots.
Cool down before you eat. Resting in a shady spot at least 10 minutes before consuming food prepares your stomach for digestion.
Keep meals small. Heat will reduce your hunger impulse because your body can’t digest as much food. Choose easily digestible foods like simple starches and fats found in crackers and nuts.
Stay wet and stay cool - This is one of the best things that you can do for yourself. Whenever you are near water, make sure to wet yourself. You can use your bandana and just by putting it around your neck, you will keep cooler.