Hi Marcia,
I don't know where your 1/2 is (Virginia Beach RnR???) but they are usually earlier so that may help with the temperatures. Still, certain parts of the country can be extremely hot early in the a.m....especially in August.
I would do some of your training while it is hot outside, just to allow your body to adjust to the temperatures. Make sure water is available immediately, even if it mean carrying a bottle in your hand. Yes, it is uncomfortable but dehydration is a serious issue! You may want to consider electrolyte tablets...Hammer brand has an endurolyte tab that I just love! Still, make sure to get gatorade or some other sodium/electrolytes in your system as soon as you are done running...or even carry that with you versus the water. You do NOT want your sodium levels too low, it is extremely dangerous and sometimes deadly. You'd be amazed at what we lose through sweat! be cautious of the breezy day when it feels like you aren't sweating...YOU ARE and need to replenish!
Now to answer your actual question (lol)...I think they say distance runners should be at about 65% carbs, 20% protein, 15% fat...roughly. Before a run, I like oatmeal a few hours before a race. During training, I fast...just a cup of coffee. You need to play with it and see what works for you...training runs are the best time for this! Some like wheat toast with PB and a banana. Your going for easily digestable foods that will give you sustained energy. Right after a run, I like Endurox R4 recovery drink or a mixture of Gatorade and vanilla protein powder (carb to protein ratio of 4:1)
Also before a race...I think carb loading is one of the most misunderstood concepts amungst runners. You shouldn't stuff yourself with pasta and bread the night before. About 12-14 hours before the race start, have a sensible sized dinner that has a good amount of carbs...pasta and bread is the norm and works well for most. Just don't stuff yourself with an "all you can eat" before you go to bed. A late dinner doesn't allow the food to digest and get enough of it into your system. Then later that evening, I snack on popcorn or multigrain wheat thins (carbs, wheat and SODIUM) or honey wheat pretzels. Play with this during your training and see what excites you!
Experiemnt with it all...that is the whole fun of it! Ask your friends what they eat and their rituals. What works great for me may have you darting for the port-o-lets at Mile 3!!!
Whatever you do...don't make any last minute changes on race day!!!! Not your food, clothes, drink (before, after and during the race), shoes, socks, sunglasses, SUNSCREEN...all of it! If you haven't tried it or used it in a training run...leave it at home!!
NOTHING NEW ON RACE DAY!!!!!!!!!!! NOTHING!!!!!!