I know of only two ways to be elegant in triple digit heat.
The first is to go find air conditioning in a place like a movie theater or Nordstrom (drink Pellegrino in the cafe). Bring a sweater. Stay there until evening.
The second is to slow down. Drink lemonade. Stay in the shade. Wear cool, loose clothes. Take a nap. Don't do much of anything. Go swimming if you can. Eat something you don't have to cook like a caprese salad. Look at clouds if there are any. Dream.
But perhaps the second is good advice on not so hot days too. Stay cool, my friends, stay cool.