The idea about taking a Cold Shower as soon as possible after a Hot Sauna or tub soak is to change the Protein isotope from the Acidic version into the Alkaline version of the Protein isotope !
As the longer you wait or if you do not take a cold shower, then the body may tend to stay on the Acidic side and not show as much improvement as fast !
But a person must do the best they have oppertunity !