The National Weather Service has issued an “excessive heat warning.” Officials are advising the public to limit outdoor activities, wear light and breezy clothing, and guzzle water. I should probably be stockpiling items from the frozen food section, and yet I can’t stop thinking about an egg. And a track of sidewalk. And a little frying session.

For the weekend, meteorologists are forecasting triple-digit temperatures with 40 percent humidity. In these extreme conditions, our hair could catch on fire and our sunglasses could melt off our faces. But we must seize this moment. We must uncover the truth. We must lasso the sun and determine whether we can actually fry an egg on the sidewalk.

But first, ewwww. Do we really want to eat food prepared on a surface covered in dirt, insects, gum, microbes and chicken bones? And secondly, concrete will not heat up to 180 degrees, the minimum cooking temperature. It won’t even reach 120 degrees, the temperature that shatters the dreams of many budding germs.

However, with the right setup, you can cook using only that big burner in the sky as your heat source. The folks at Solar Cookers International whip up food a la soleil all the time. When I called the organization for tips, executive director Caitlyn Hughes was dehydrating squash in the office parking lot in Sacramento. Earlier in the week, the staff had baked sun-smacked brownies for a colleague’s birthday. Hughes’s team typically works with the United Nations and developing countries on solar cooking devices (the nonprofit created the CooKit for refu­gee camps in the 1990s), but on the eve of the heat advisory, she offered advice to a Washingtonian with a rooftop deck and a carton of eggs.

“You need something reflective to direct the heat and also to trap and absorb the heat,” she said.

The something reflective could be a cardboard box corner covered in aluminum foil or the CooKit, which resembles a disco proscenium stage. (You can find the blueprints online .) If you still have your suntanning shield from your Bain de Soleil days, haul that pariah out for a good cause. To contain the heat, Hughes recommends using a black pot or pan made of a thin, dull material. Too thick will take too long, and shiny will throw the rays back at the sky. She said to place the cooking receptacle in an oven-roasting bag or Pyrex clam shell, made from two glass bowls, creating a bubble the heat can’t escape. If you have ever sat in a hot car with a black interior and closed windows, then you know what the egg is going to feel like.

Other tips from Hughes included to cook during the sweet (sweaty) spot of noon to 2 p.m.; cut food into small pieces so they will cook faster; and wear sunscreen. She also gave me the number of a culinary sun goddess.

At high noon, Peg Barratt rolled into The Washington Post’s office. The D.C.-based board member of Solar Cookers International was carrying several handmade solar cookers, a bag of black pots with covers, oven mitts and gingerbread cookies she had baked in her backyard that morning.

We started by placing a cracked egg in a pan, plus two strips of bacon, so the yolk wouldn’t get lonely. Into a separate container, we poured cornbread batter. Peg adjusted the contraptions so they fell on the shadow of her head — a direct zap by the sun. Less than five minutes into the experiment, the thermometer on the cornbread read 120 degrees, nearly 30 degrees hotter than the outside air. Twenty minutes later, it hit 200.

“You’re never going to overcook it,” she said, as we slipped inside to cool off. “Rice won’t burn, polenta won’t burn, cake won’t burn.”

A half-hour later, we peeked at the bacon and egg. The egg white was turning opaque and the yolk was solidifying. The bacon was slightly crispy around the edges, though the strips jiggled like ectoplasm. The air smelled lightly of Denny’s.

We built more cookers and put two whole eggs inside one, gingerbread cookie dough in another, and a husk of corn and a sweet potato in a third. Then we left our food for some alone time with the sun and went downstairs. We found a section of sidewalk without any overhead obstructions and broke an egg directly on the pavement. It started to slide toward the curb. We opened another on the black asphalt of K Street.

“It didn’t sizzle,” Peg noted with a tinge of disappointment.

A woman in a silver SUV drove up and parallel parked over our egg. I looked at Peg hopefully and said, “The car is trapping the heat.”

About an hour into our experiment, we were ready for the big reveal. The egg accompanying the bacon had transformed into a diner-quality sunny-side-up with a hard yolk and no wobble. The bacon shimmered like a slug after a rainstorm: cooked, but pale and, well, flaccid. You could eat it, but why would you? The cornbread was golden and crispy. The cookie had the consistency of thick pudding. The corn on the cob was ready for a pat of butter; the potato might require a trip to the dentist to repair that busted crown. The eggs had baked to hard-boiled perfection, with no water necessary. We had also thrown into a pan two slices of bread sprinkled with cheese. After several minutes, the cheddar morphed from shredded to stretchy. We slid the egg into the maw of the melted cheese sandwich for a true taste of heat-advisory sunshine.

We divided our meal into two categories: the successes and what Peg optimistically called the “needs more cooking time.” The only really misses lay forlornly on the street. A new car was parked over the K Street egg, and the one on the sidewalk was smeared, a cooking tragedy caused by a shoe.

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