This video explains how Ishnaan Therapy (Cold Shower) works and why you would want to do it. I have been practicing this for two months and it has improved my skin tone and immune system. It is also great for showing your ego who is in charge because I have to say that every morning part of me doesn't want to get in the cold shower! And part of me knows I will feel great afterwards and be healthier. The ability to do things that are good for me that are uncomfortable for a few moments is good training for will power.
When the cold water hits the surface of your skin (which has four layers) all the blood from way deep inside your body rushes to the surface in self-defense, vastly improving your circulation on the spot. This is called Hydrotherapy. It strengthens your entire nervous system. People pay huge sums of money for what is now called "Hydrothermal therapy" when in reality all you need is cold water!
But first, before you get wet, massage your body all over with a little oil. Oil is more easily absorbed by the skin when it is mixed with water--and you won't be greasy afterwards. Almond oil is highly recommended since the almond contains so many minerals, and it nourishes the body through the pores of the skin.
Go in and out of the water four times, constantly massaging your body until the water no longer feels cold. Be sure not to miss the area under your arms, which is where the parasympathetic and sympathetic nervous systems meet. You can even stand on one foot and massage the top of it with the other foot. Women, be sure to massage your breasts.
"Your first victory of the day! You will probably become very holy the moment the cold water hits your body, because it is likely you will shout, "Oh my God!" You might try exclaiming "Wahe Guru" ("Wow, God is Great!"). Remembering God is always a blessing.
Dry off briskly with a rough towel till the body really shines; put on loose, comfortable exercise clothing, and you're ready to do your sadhana, your personal daily spiritual practice. God bless you, you're bound to have a wonderful day!
From the Book The Flow of Eternal Power by Shakti Parwha Kaur Khalsa