women s surfing. lydia jacoby, the 17-year-old from alaska, is putting out the surge of her career! reporter: and first-time olympian, 17-year-old lydia jacoby, won gold in the 100- meter breaststroke. back home in alaska, a state with only one olympic-length swimming pool. (audience goes wild) her high school classmates were ecstatic. individual gymnastic events begin on thursday, but biles will not comment if she s competing or not. she said in the press conference she s going to take time to evaluate where she is and decide day by day. norah. o donnell: we ll be watching. thank you so much. tonight, much of the central u.s. is in the grips of another dangerous record-breaking heat wave. more than 56 million americans are under heat alert from montana all the way to georgia. cbs lonnie quinn is here with the forecast. hey there, lonnie. reporter: another summer day, another heat dome we re talkingr about. today the record heat anywhere from wyoming, south dakota, nebraska. l