Ooops , I always use hot water..

We have a older tub - (steel/porcelain?? - not plastic or fiberglass,)so it sucks some of the heat out of the water til the metal gets warmed up.

I did read somewhere it is best to rinse off after soaking, but not sure if that was more for bath salt mixes instead of plain Epsom salts.

I have a sea salt/Epsom salt mix, sometimes I rinse off & sometimes I don't.