I usually start my day with a cold shower and end it with a hot shower.
There are many benefits of this practice.
Cold water stimulates immune system, tightens skin, accelerates metabolism, etc.
Hot water relaxes muscles, clean pores, reduces anxiety, removes grime, etc.
I think a combination of both could help you a lot with your health.
Cold for keep you focused and active through the day (after waking up).
Hot to relax and rest (before bed).