Wader ware?

[yaky yak]

Finely after 7 seasons of freezing my cheeks off, I went and bought some waders.
I have always been worried about swimming in them if I was to flip or what not and end up in the water. I know to ware a belt with them, but still nervous.
My question is what do you ware under them? I have neoprene farmer john style with the stocking feet. a pair of sweats be enough or shorts? In other words are the waders them selfs pretty warm or do they just keep you dry. I don't want to be to hot or cold.
The thought of being dry and warm has over come any fear I have of drowning in them. I know their safe.