No matter how you looked at it, hanging upside down in the Vermont sky or shivering on the sidelines of a south Florida tennis court, baby, it was cold outside. And because the icy winter wasn't about to go away soon, if ever, people simply had to get on with whatever they would have been doing if they were warm. At Boca Raton, Fla., it was in the 40s at courtside for the Grand Slam Tennis tournament. At Stratton Mountain, the country's top women freestylers assembled for the $65,000 Colgate World Trophy competition, the premier event of their season. Much of the time they could scarcely warm up enough to buckle their boots, let alone attempt a double helicopter or triple backscratcher. During workouts the wind-chill factor was —74�, but the actual temperature rose to 9� for the meet. When the last skier had come to earth, the overall winner was Marion Post of Averill Park, N.Y., the 1976 champion, who earned $8,270 to help warm her weekend. At New York's Aqueduct, Steve Cauthen took to the weather as if chilblains were merely the name of another horse. From Monday to Friday, a stretch when post-time temperatures edged above freezing only once, the spectacular 16-year-old apprentice jockey booted home 11 winners. On Saturday he got really hot. Cauthen drew a mount for each of the day's nine races, run at 22�, and finished in the money every time: six winners, one second and two thirds, giving him 40 winners in two weeks. They race year round in New York nowadays, but the trout season doesn't open until April 1, which is a blessing, for the beloved Beaverkill has about a foot of ice. And if one of the nation's finest trout streams nearly freezes over, can spring be far behind? You bet it can.