Ayurveda advocates the warm water bath. Yoga advises the use of cold water. The body cools minutes after exposure to hot water as the blood vessels that dilated with heat contract in reaction. A cold shower has the opposite effect, making you warm within a few minutes as the vessels constricted by the cold dilate.
A mental bath should always accompany the physical bath, to awaken the mind and enkindle its digestive fires. Specific bathing mantras do exist, but any song or chant which you enjoy, will help satisfy your mind.
Vata people, who require heat, after a warm shower or bath can rinse with cold water to preserve the warmth.
Pitta people should adapt themselves to cool showers or baths (but not cold) to remove their excess heat.
Kapha people should also adapt to cool water, to invigorate themselves.
However, no one should bath for one hour after eating, to avoid drawing blood away from the gut where it is required for digestion. Also after our yoga practice we should wait for a minimum of 30 min before taking shower or bath. The body contains certain essential minerals, which come out of the body along with the sweat. If bath is taken immediately after yoga, these minerals will be lost. We should shower or bath before our yoga practice.