If your body is otherwise healthy then you should just let it do its thing. If you're not otherwise healthy then the list of possible answers varies (into opposites) depending on what else is wrong. Example: (as I understand it) a warm bath should dilate blood vessels in the skin. A cold bath will contract surface vessels and dilate deeper ones. Hot and cold aren't the only things that will dilate/contract blood vessels though -- a bruise for instance...

A bruise is a result of damaged cells. There will be cleanup and rebuilding going on. Conscious Interference is unlikely to help unless you know exactly what to do, but in that case you probably also knew what to do to build a strong healing response so just relaxing would be your best bet.