Thanks everyone!

I don't usually bath because I struggle to get back out, the CRPS started after a knee replacement and my other knee is useless and so I can't walk anymore.
If I do bath, I have to let the water out whilst still in the bath and dry off and then dry the bath, that gives me some grip and my wife then helps me out, all of that leaves me ready for a sleep and in more pain!

Its weird because I used to wear shorts all year round, the cold never bothered me, but now I'm always under a duvet.

I shall try the Epsom salts, thank you