It really depends how much you heat them, this applies to any substance, and what you're looking for. I'd suspect that chlorite would decompose on moderate heating, but you can melt NaCl, or even vaporize it, if you got it hot enough. You probably don't want to go that far, but how far? I just don't know.
The only reaction I found was
4NaClO + KI + H2O --> Na + I2 + O2 + KCl
OK. I want to know where you found
that one, I wouldn't expect free sodium metal was that easy to make.