I cheat.  I take a fully hot shower just the way I like it but turn the water to cold for 30 seconds in the middle.  I try to stay under for 15-second each side.  But most of my body is hanging out of the cold water.  I screech the entire time.  Matt laughs and tells me my noises are too inappropriate to do this when we have house guests over the weekend. 
After 30-seconds I turn the water back to hot and warm up.  I find that my face feels really good after the splash of cold and so I don’t hit my face with hot water again.  Still, I know I’m cheating.  I’m nowhere near the three minutes Dr. Oz’s guest  recommended.  Half my body is always hanging out of the water.  And since I reheat I don’t get the invigorating feeling I got after the first day.  But I know I won’t stick to this challenge if I have to get in cold water and stay in cold water.  My new goal is to build up the time (and actually get my body in the water).
Personal Euphoria