Group 1 - The article discusses the extreme heat in Shanghai during the summer, with temperatures reaching up to 40°C after the end of the plum rain season on June 29 [5][12] - It highlights the public's adaptation to the heat, including changes in shopping and outdoor activities, with many preferring to stay indoors with air conditioning [6][7][8] - The article draws a parallel between the current summer heat and the hot summers of the late 1990s, emphasizing the cultural and social changes in Shanghai during that period [13][14] Group 2 - The article features photographer Xu Haifeng, who documented the vibrant street life of Shanghai during the late 1990s, capturing the unique fashion and lifestyle of the city's residents [14][17] - It notes the coexistence of traditional and modern fashion styles, with people wearing both trendy outfits and classic garments like the "old man shirt" [27][39] - The introduction of air conditioning in the 1990s is discussed, detailing the challenges residents faced in using them due to infrastructure limitations [48][51] Group 3 - The article mentions the cultural significance of sunglasses in the 1980s and 1990s, which became a fashionable accessory as international brands entered the Shanghai market [33][35] - It describes the social dynamics of cooling off in public spaces, where residents would gather to escape the heat, reflecting a communal aspect of life in Shanghai [54][60] - The narrative concludes with a comparison of past and present summer experiences in Shanghai, noting the continuity of outdoor leisure activities despite changing social norms [62][63]