Fleece hoodie sweatshirts in spring-summer, Do you wear them?

The weather is getting warmer now. it was 80 degrees out yesterday and every now and then I'll see young teen or college age girls wearing shorts with big heavy sweatshirts. Is this a style or trend? I'm hot in a tank top or t-shirt and some girls are wearing fleece pull-over sweatshirts with their hoods up and the sleeves covering their hands. Is it still cold to some people?