Despite a couple days of oppressive heat at the outdoor Mt. Hood Community College pool in Gresham, Ore., this year’s U.S. Masters Swimming Summer National Championship was one of the best in many years. Thirteen athletes broke 35 individual world records, with several others leaving the meet with new national marks. And, befitting an Olympic year, the roster was filled with Olympians who were either continuing their successes in the pool or re-entering the sport after a few years away.