Hot pants were the rage in the early 1970s having found great popularity years earlier among European prostitutes.
Hot pants were the successor to the miniskirt, succeeding in showing more leg, more cheek and more attitude than had been previously displayed.
While very popular among many young women (and most young men,) they were frowned upon in the workplace as well as in many social arenas (a number of prominent restaurants forbade them from being worn by patrons.) Some businesses took full advantage of the fad (notably Allegheny airlines, even made them a part of the company uniform).
Surprisingly, this fad only lasted during colder months and faded before the warm weather came, perhaps because showing legs was more titillating during the winter months when they weren’t expected.