By the time Ted Barber Jr. soaked his cooling towel for the second time, the afternoon was winning its war of attrition. Frozen water bottles had melted away, lemonade had been drained to the last drop, and each fresh drenching of Barber’s towel evaporated within moments.Barber and his wife were armed for the afternoon in section 218A of the Los Angeles Memorial Coliseum — hats on their heads, cooling towels at the ready, two frozen water bottles apiece. A few hours beneath an unobstructed sun steadily dismantled those defenses.USC fans faced a fairly simple calculation Saturday: A game against San José State, a nearly six-touchdown underdog added after the Notre Dame rivalry went on hiatus, weighed against four hours baking in 94-degree heat with scarcely a patch of shade. By kickoff, acres of exposed red seats suggested plenty had done the math and found another way to spend their Saturday.Barber followed USC home and away for six seasons without once leaving early, surviving even the bleakest days of the Clay Helton era. Lightheaded when he stood and worried about his wife facing heat exhaustion, the two left before halftime.“As soon as we got to our seats, oh my god, the sun was just beaming,” Barber said. “We quickly realized that, yeah, I don’t think we’re gonna be able to make it.”Roy Nwaisser, the longtime fan known as “USC Psycho,” has not missed a Trojans game since 1992. Though he stayed through USC’s 42-26 trouncing of the Spartans, he described the choice confronting less obsessive fans: How much discomfort could this game justify?“There’s no world in which a 110-degree heat index is not going to affect the attendance at the Coliseum for the first game of the season against San José State with a 40-point spread,” Nwaisser said. “That’s the decision people are making: Is the agony going to be worth it for this game?”