assuming this isn't medical advice seeking and that this individual is otherwise totally healthy, I can say that totally healthy people can get pitting edema from this and it is generally harmless
not all dependent pitting edema is a big deal
OTC compression stockings instead of crappy socks and frequent walks through the day, elevating the feet in the evening, can help
I would tell this person to wear comfortable fitting shoes and socks, and if they still had this after a day on their feet, to see their PCP for a checkup, listening to the heart and lungs even in young people doesn't always turn out to be a waste of time, a basic checkup for this wouldn't be remiss although it's likely nothing