"On weekends in summer the town empties," wrote E.B. White in his definitive essay "Here Is New York." That comment may apply to Manhattanites, but it neglects the folks who file into the city in the infernal depths of midsummer to find amusement, enlightenment: entertainment. On a Friday evening when the current heat wave was on the horizon, I stood outside the entrance to the Vivian Beaumont Theater, where War Horsekeeps playing to sold-out houses, and watched the world make its way in.

And I do mean the world. While trying to appear unobtrusive I overheard chatter flowing in the following languages: English, Spanish, Russian, French, Hebrew, and a Slavic-sounding tongue I couldn't quite place. War Horse may not yet have reached the ultra-international status of Cats ("Memory" is universal) or Oh! Calcutta! (nudity knows no national boundaries), but its status as a must-see is rapidly being cemented globally. 

As the summer flows past, I have noticed more children in the War Horseaudience. This is not a given. Just because school is not in session does not mean that the kids are more available for Broadway outings. Parents will nod in agreement when I say that, upon asking a Long Island friend of mine weeks ago to name a date this summer to get tickets for her 12-year-old son and 15-year-old daughter, she replied, "Jason has hockey camp until the end of July and a West Coast trip with his dad for two weeks in August. Sarah has music camp in Michigan until August 7th and she's going to see her cousins in Maine on August 10th. Can you get us four tickets on August 9th?" 

Theater attire also alters in summer. At the Beaumont that night, you could easily spot the small-town tourists: they were in their Sunday-meeting best. I was unsurprised by the number of entering women in shades of alabaster and ivory and pearl; as the American designer Bill Blass once told me when I asked him for the 5 Eternal Rules of Fashion, "There never was and never will be a better color for summer than white." I was a little startled by the number of people showing up for War Horse wearing tank tops and shorts. (As on airplanes, these are generally the ones who complain that the air-conditioning is set too high.) I was positively agog at the sight of a certain rather tall woman, speaking Russian to a nattily attired gent, who was wearing something so short I couldn't tell if it was a shirt or a dress: a shmess. (A word, by the way, not found in my Yiddish dictionary.) 

According to War Horse cast members, the summer heat affects not just attire but mood. War Horse's actor and archer extraordinaire Ariel Heller told me backstage that there was a matinee audience this month who couldn't stop cracking up. "They were giddy," Heller said. "People were getting mowed down in the second-act and they were laughing." I'm not sure we can attribute these high spirits to the weather, though. Perhaps I should spy on the lobby bar sometime and see with just how heavy a hand the intermission cocktails are being poured. Even the sternest of accountants, however, could hardly blame the servers: it's just too darn hot. 

Brendan Lemon is the American theater critic for the Financial Times and the editor of lemonwade.com.