Fly Fishing from the bank - is it done?

Hello All,

I know nothing about fly fishing but my brother-in-law is coming out here
to fish and I thought I would try to learn something before he gets here.
So I signed up for a course and I just took my first fly fishing class last
night (first of 5 in the course). And I had a question that only occurred
to me after I left.

In the course they talked about rods, reels, line, and waders. When
talking about the waders they told some horror stories about people fishing
in cold water in the wrong gear and getting hypothermia and the like. On
the way home I got to wondering why you wouldn't just fish from the shore
if the water was really cold. So my question is: is it possible to fly
fish from the shore/bank or do you have to be in the water to fly-fish.
They did mention being in the boat but most of discussion seem to center
around standing in the water and how there are a number of dangers - like
hypothermia or falling over and getting water in the waders and the like.

TIA
Bob