Some like it hot. Rick Carey likes it cool, which is a major reason he set a world 100-meter backstroke record in the rain today.

Carey sliced .19 of a second off the mark he set two weeks ago, clocking 55.19 for his second gold medal of the Pan American Games.

With Carey leading the way, the United States captured all six golds in swimming and diving today. That makes the five-day bag 25 in 28 events, with one day of competition remaining.

The rain cools off and tightens up most swimmers, who come from warmer climates than that of Carey's home town of Mount Kisco, N.Y. Since it has rained four straight days at the Pan Am pool, it was the cold that had been blamed for the slow times that prevailed since Steve Lundquist set his 100-meter breaststroke world mark on Wednesday.

"I like chillier water than most swimmers and this pool is colder than Clovis (California site of the recent U.S. championships)," Carey said. "(Matt) Gribble, for example, likes it warm and he had trouble in the 100 butterfly. If it had rained really hard, it would have affected my swim, but it was just enough to cool things a bit."

This was Carey's fourth time under 56 seconds and he thinks he can go below 55 soon, possibly as early as Monday, when he swims leadoff in the 4x100 medley relay and is eligible to set a record.

"Every time I go under 56 I get more experience and I'm ready for the next one," Carey said. "My mind is ready for the 54 barrier and I expect to be in the 54s either tomorrow night--although I'm making no prediction--or next year.

"My start was okay tonight and I got streamlined underwater and came up good. I smacked the turn, my best in a long time, and I think the record was in the turn. The last 10 meters I died, but you can't have everything."

Carey, 20, a University of Texas junior, is looking forward to the medley relay, not only because of his record chance but because for possibly the first time in history four world-record holders will swim as a unit.

Carey (100 backstroke), Lundquist (100 breaststroke), Gribble (100 butterfly) and Rowdy Gaines (100 freestyle) will be aiming for the world record of 3:40.84 they established in the World Championships in Ecuador in 1982.

"We swam together last year in the world games and really hit it," Carey said. "The world games had been a big downer and we wanted to lift the team by creaming the Russians. I don't know if we have the same hunger this time."

Other U.S. winners today were Craig Beardsley, with a Pan Am record of 1:58.85 in the 200-meter butterfly; Tracy Caulkins, 2:16.22 in the 200-meter individual medley; Tiffany Cohen, with a Pan Am mark of 8:35.42 in the 800-meter freestyle, and Greg Louganis in platform diving. The U.S. women took the 4x100 medley relay in 4:12.99, another Pan Am record.

Beardsley earned a close decision over Brazil's Ricardo Prado and Venezuela's Rafael Vidal. After the victory ceremony, the swimmers and other participants were forced to stand in the rain while the crowd honored Vidal by singing the Venezuelan anthem.

Canadian Tom Ponting, who finished fifth, collapsed after the race and had to be wheeled off on a stretcher.

Susan Rapp, formerly of Alexandria, Va., was third behind Caulkins and Canada's Michelle MacPherson in the 200 IM. Caulkins had two false starts and said, "they've been starting us very quickly and I didn't realize that this time we had an American starter."

Louganis rolled up 677.58 points on his 10 dives to beat teammate Bruce Kimball by 23. On the last four dives, the amazing Louganis earned scores ranging from 79.20 to 91.80.

The United States stretched its overall gold-medal lead with 18 championships for the day, to 12 for Cuba.

Boxers Louis Howard and Evander Holyfield moved into the semifinals with easy victories, and the United States ended Canada's unbeaten streak in women's basketball with an 87-79 victory, behind Lynette Woodard's 22 points. The U.S. baseball team remained unbeaten, thanks to a two-run homer by Ben Abner with two out in the eighth inning that beat Panama, 4-3. In women's gymnastics, Lucy Wener, 16, and Yumi Mordre, 17, won gold in the uneven parallel bars and floor exercise, respectively.