Wear a PFD and if you use waders;
always wear a wading belt.
I lived in North SD County most of my life; but since I moved up to the PacNW; I've learned a lot about what to wear in cold and wet weather. You can see
what we wear for cold and wet weather here.
50F water here is tropo; it's mostly windy and rough. Almost always on your own.
Take a tip from the Boy Scouts;
Be Prepared.