The action of heat: dilates blood vessels, causing more blood to circulate near the surface of your skin. This action bathes cells in oxygen-rich blood and allows a small amount of toxins to be released through the skin. The action of cold: constricts your capillaries, and shunts the blood to the core. It is here that the majority of toxins are removed as the blood filters through the internal organs. The blood is then replenished with fresh oxygen and pumped back to the rest of the body to begin the ongoing cycle. The process of stimulating the circulatory system with hot and cold, detoxifies and bathes your cells in fresh oxygen-rich blood; bringing youthfulness to your mind and body.
Hydrotherapy
Soak up the Benefits of Hydrotherapy – Massage Magazine, April 2015
Dead Sea bath salts for the treatment of rheumatoid arthritis – Clinical and Experimental Rheumatology, Jul-Aug 1990
Hot/Cold Immersion Therapy – Wikipedia
Benefits of Cold Showers: 7 Reasons Why Taking Cool Showers Is Good For Your Health – Medical Daily, June 2014
Scientific Evidence-Based Effects of Hydrotherapy on Various Systems of the Body – National Center for Biotechnology Information, May 2014
Infrared
Far infrared radiation (FIR): its biological effects and medical applications – Photonics and Lasers in Medicine, 2012
What You Need to Know About So-Hot-Right-Now Infrared Spa Therapy – Bloomberg, March 24 2017
Far-infrared saunas for treatment of cardiovascular risk factors – Summary of published evidence, National Center for Biotechnology Information, 2009
Sauna
Saunas help you live longer, study finds – Associated Press, February 2015
8 Unexpected Benefits Of Sauna That Will Impress You – Lifehack, April 2016
Wet Sauna Benefits – LIVESTRONG.COM – September 2015
Sauna Bathing and Incident Hypertension – American Journal of Hypertension – June 2017