On the eve of the United States' 250th birthday, the nation's capital decided to become a sauna. Sweat-soaked tourists pressed electric fans directly to their foreheads as the record-breaking heat wave that roasted the Midwest earlier this week turned Washington, D.C., into hell. Temperatures peaked at 102 degrees Fahrenheit, with a heat index of 117. The sky was cloudless, and the humidity was encouraging one journalist to lie down and cry. It was difficult to believe that D.C. has been four degrees hotter than this twice before, in August 1918 and July 1930. Tomorrow may be even more surreal, with another day of oppressive heat and throngs of tourists in town to see what the president has billed as the biggest fireworks display in human history.

On Tuesday, August 6, 1918, the asphalt was so soft that heel marks of pedestrians were left in it, according to The Washington Herald. Josephine Lehman, a young secretary in the Department of War during World War I, wrote home that the cement pavements burned one's feet through the soles of shoes. In an apparent first, the head of the city police let his officers patrol without jackets. Indoors, fifty government staffers in the State, War, and Navy Building - now called the Dwight D. Eisenhower Executive Office Building - were taken to the emergency room due to heat, the Evening Star reported. City officials ordered ice-cream parlors to stop making ice cream to conserve ice supplies and waived occupancy limits at community pools, worried people would pass out in line. Each pool ended up holding 600 to 700 people.

The pools were packed again on July 20, 1930, when D.C. hit 106 degrees for the second time. Thousands fled to the beach, which was "too hot for all but the most daring," the Herald reported. The paper ran a photo of kids splashing in the Reflecting Pool; a cop in the background seemed happy to let them play. The Washington Daily News reported that a Sunday throng still showed up at the National Zoo, where staff hosed down elephants and the hippo stayed in its bath. Thousands slept on benches, fire escapes, and parks, especially Potomac Park, where steamship passengers could see them playing bridge and dancing in the river breeze. Beyond the city, forest fires raged across Maryland; the Washington Times noted that volunteers were loath to brave the intense heat.

Today, D.C. residents and visitors have air conditioning, which is good because many historic cooling sites are closed. Yellow tape separated one journalist from Potomac Park; a park police officer wagged his finger at him. For fireworks and other 250th festivities, the National Mall is a maze of chain-link fences, megastages, Porta Potties, and temporary Greco-Roman structures. The incredibly shadeless Great American State Fair, where dozens were treated for heat-related problems, was canceled until 5 p.m. When a journalist asked a National Guard member if he could walk to the Lincoln Memorial, the guard apologized for the heat and admitted to "suffering" in military fatigues - no loosened uniform standards here. No one could cool off in the Reflecting Pool, which is fenced off due to algae that bloomed after President Trump's failed attempt to beautify it. Black bags of fireworks lined its perimeter. As close to the water as people could get were about five protesters in inflatable frog costumes, one carrying a sign reading TEAM ALGAE. One frog protester, Val, had stuffed ice packs into her sports bra. About 20 fighter jets flew overhead, leaving red and blue smoke.

At the National Zoo, no one was hosing off the elephants, but an employee said they have three wave pools and staff run showers for them. The pachyderms seemed fine until sonic booms from the jets began; one elephant, 51-year-old Swarna, ran around her enclosure like a bucking bronco. A mother and daughter who flew in for the Fourth of July told their dad to skip the zoo: the heat was "worse than Disney." At a packed community pool, a mom of two, Lanay Brown, said she brought her kids and nieces most weeks since school let out, but today was the first they had to wait in line. A baby named Max, turning 1 in four days, sat next to the kiddie pool in his own inflatable pool, biting it. His dad, Andre, who moved from Florida, said this is the hottest he's felt since leaving the state five years ago. A Floridian journalist waded into the pool in her dress and felt relief similar to what D.C. residents felt many summers ago. She went home thinking this was maybe the most American day of her life, with poolside rap, warplanes, and many, many patriotic T-shirts. It was definitely the hottest.