Wearing skirts

In my era I was taught to always wear a slip under my skirt. In a way I can see how that makes sense because of the gauzy material summer skirts are made of. However, it's summer. The slip just doesn't fit in with keeping cool. On the other hand I don't want to be on "exhibit" nor appear inappropriately dressed I've seen many women wearing skirts without a slip. I can see their legs. Seeing legs is not offensive. After all, we wear shorts. What's the trend these days? Slip or no slip???