Question from my Aunty (she's dealing with a ton of bricks!) Few days ago Uncle wore Hawaiian Slippers (as he always does) to visit a neighbor few houses down. After he returned home and removed his slippers there were red indented marks on his foot. But 1 hour later these red indented marks were still there. Why does this happen? Is this due to a condition? Or something with his skin? I don't know what to even google ????