Most people have heard the “old wives tale” about how unhealthy it can be to move frequently between very hot and very cold spaces. This rapid change in environmental temperature is either healthy or unhealthy, depending on the source. The science behind the idea is called contrast therapy. When it involves water it’s called contrast hydrotherapy. Is this kind of therapy useful? Is it unhealthy or healthy?
I first encountered the idea while researching sanitariums. One of the rooms in a sanitarium I studied was devoted to “water treatment.” Intrigued, I read more. I learned that contrast hydrotherapy has been in use for a long time.
Many native people have traditions like the Native American sweat lodges. A sweat lodge uses heat to force the body to perspire. Some cultures add cold water to the mix.
Ice baths are used by some societies to treat illness. We use ice baths today to protect the brain from damage during surgery and other treatments. People who have drowned in icy water have been revived long after what would normally be a fatal period of time with no oxygen, and have experienced little or no ill effects from their experience.
Clearly, there is something at work here.
When your body is cold your skin contracts. Capillaries, arteries, and veins in your skin shrink and begin to collapse. This forces blood to leave the skin and other tissues where it may have collected in a circulatory eddy and join the larger tributaries of the blood stream. When your skin is hot the opposite occurs; migration of plasma and red blood cells move from the core of the body to the skin and extremities. The invigorating effect experienced by the individual is no fantasy.
If you read old medical texts you’ll find many claims about this kind of treatment. It seemed to be used a lot with the mentally ill, with the elderly, with people suffering from paralysis and similar mobility limiting conditions. It must have been horrifying to be subjected to this therapy if you did not understand what was going on (sometimes it was used as punishment as well). Some modern therapists still use this therapy to treat injuries, and it can be effective in the hands of a professional. I’ve tried it myself and can certainly say it is invigorating, if nothing else. I also discovered by accident that if I subject myself to an icy bath during Winter, when I remove myself I don’t seem to mind the cold so much. The effect lasts for weeks after the ice bath. Is that just me, and my imagination, or have I stumbled on to another use for contrast hydrotherapy?
It is worth noting that during my studies I found nothing to indicate that moving between hot and cold areas does any damage to the human body, aside from making you momentarily uncomfortable.
Have you ever tried temperature contrast therapy? What was your experience?