It's 95 degrees. The power's out because a squirrel fell into a transformer. Or you've eschewed greedy, corporate utility companies and decided to live off the grid. Because of the heat, a campfire is intolerable. How do you cook?
Answer: A solar oven.
You can buy a solar oven via the Internet or make one at home. When I lived in Texas, where it's often hotter than the ninth circle of hell, I once concocted a solar oven using a wheelbarrow, aluminum foil and cardboard (windshield sun reflectors also work and are easier). The wheelbarrow allows you to move the oven around the yard for maximum rays, while the foil reflects the heat and light onto the pot of food.
Cut the cardboard into the shape of fan blades and cover with aluminum foil. After listening for alien communications, place the foil-covered cardboard in the wheelbarrow. Put your food, such as canned black beans, in a dark-bottomed pot or pan. If you're cooking vegetables, drizzle them with olive oil and add a couple of tablespoons of water so they will steam. Place the pot in a large freezer or baking bag and top with the lid, then set it in the wheelbarrow in direct sunlight.
For the next two hours—a tad longer if you're cooking root vegetables—return to your house, do macraméé, tie-dye some T-shirts, smoke pot and/ or take a nap.
Wearing sunglasses, approach the wheelbarrow. Wearing oven mittens, remove the lid and open the plastic bag. Voila! Dinner is served.
Solar ovens are frequently used in Africa, where electricity is at best intermittent and at worst absent; wood can be scarce, not to mention dangerous to gather in some refugee camps.
Solar cooking resources abound on the Internet, although if you have no electricity, you'll need to bike to the library to get on a computer.