Paris authorities recently authorized swimming in a section of the Saint-Martin canal amid a heatwave, a move previously prohibited. Despite the change in regulations, attendance has been surprisingly lower than during a period in May when swimming was illegal. Officials have specifically banned diving or jumping from the canal’s bridges, but this has not deterred all individuals. The decreased turnout suggests a paradoxical effect – the act of legalization appears to have diminished the appeal for some. This observation raises questions about the motivations behind the previously illicit activity and the role of restriction in driving participation. The city’s decision aimed to provide relief from the heat, but the response has been unexpectedly muted. Further observation will be needed to determine the long-term impact of the policy change.