It was a hot, muggy day in Guelph, Ontario, in the summer of 1991, and 19-year-old university student Gwen Jacob decided she had as much right as a man to cool off by taking a walk topless. Her subsequent conviction for public indecency was overturned this past winter, and with summer temperatures finally on the rise, the exhibitionist controversy is heating up all across Canada. The Ontario Court of Appeal ruled in December that Ms. Jacob's topless stroll was not a breach of the federal Criminal Code because she had not violated "community standards." Traditionally, whenever a federal law is involved, courts in other Canadian provinces follow the precedent. Already, the Ontario ruling has had an effect: Police in Winnipeg, Manitoba, decided not to lay charges against a woman seen bare-breasted in public. In Maple Ridge, British Columbia, a woman celebrated Canada Day (July 1) by going topless. She threatened to sue for $245 million had she been charged. The authorities did nothing. Not that law enforcement is powerless. Ontario Attorney General Charles Harnick said that although he could not appeal the court's ruling, municipalities might be able to pass bylaws restricting the places where nudity is permitted. But as Ontario suffered through one of the coldest, snowiest winters on record, political observers doubted the need for such laws. Those pundits were wrong. With the arrival of hot weather, the ice melted and today many residents in Canada's most populous province feel they are drowning in a sea of nudity: In several cities, strippers have taken to suntanning themselves half-naked on the sidewalks outside their establishments. In Toronto, a woman showed up at a seniors' festival wearing nothing on her chest but nipple rings. Two enterprising Toronto women hired themselves out as topless window washers; at some city intersections, drivers are being intimidated by squeegee girls who appear too poor to cover up. Even small towns have been affected by the court's decision. In the eastern Ontario town of Trenton-population 16,000-Heather Genereaux pleaded guilty last month to assaulting her former best friend and neighbor Jennifer Fitzgibbon. Ms. Genereaux became angry because her neighbor insisted on cutting grass, washing her car, and sunbathing topless after being asked not to do it in front of Ms. Genereaux's 10-year-old son. Fed up, Ms. Genereaux scaled a hedge, kicked Ms. Fitzgibbon in the stomach, and ripped off the rest of the woman's bikini. Now completely nude, Ms. Fitzgibbon managed to give Ms. Genereaux a black eye. In larger cities, parents are complaining that they can no longer send their children to play in the park for fear of exposing them to women fond of exposing themselves. "But worst of all," says Lorraine McFadden, spokesman for the newly formed Coalition Against Toplessness in Windsor, "is the effect nudity is having on male attitudes toward women." She describes a company-sponsored baseball tournament in nearby Leamington that was set up so participants had to enter the field through the beer tent. "At the end of the bar," she reports, "was a sign that read, 'Ladies, pop off your top and we'll give you a beer.'" Public nudity is also damaging worker relations at a construction site across the street from the Windsor Casino, where women regularly parade topless on the sidewalk outside. Mrs. McFadden tells the plight of a female friend who is a construction worker: "The male workers are so stimulated by what they see across the street that they are constantly asking her to take off her top." The young woman fears she will have to quit her job. Gwen Landolt, a lawyer and national vice president of the anti-feminist group Real Women of Canada, points out that in their decision, the Appeal Court judges were wrong twice. A poll by the Angus Reid Group shows that fully 65 percent of Ontarians say topless women violate community standards. "Nor does this have anything to do with equality," Mrs. Landolt says. "It's just a handful of extremists turning the country upside down." Not surprisingly, there is a backlash against the Appeal Court's decision. Mrs. McFadden reports that in its first week of existence, her coalition gathered over 13,000 signatures; the organization's ultimate goal is to present the national Parliament in Ottawa with 250,000 signatures on a petition calling for Criminal Code amendments that would restrict or abolish public toplessness by women. The politicians may be getting the message. Last week, newly installed federal Justice Minister Anne McLellan announced she and Mr. Harnick will meet next month to study the issue. The move came one day after Ontario Premier Mike Harris finally declared toplessness was a problem and that Ottawa should tell the ladies to keep their shirts on.