A group of medical doctors (Tei, Shinsato, Miyata, Kihara, and Hamasaki,2007) at Kagoshima University in Japan developed a form of thermal therapy they called "Waon therapy" (soothing warm therapy) involving the repeated use of a dry sauna at 60°C.
"The patients were placed in a far infrared-ray dry sauna, in which the temperature was evenly maintained at 60°C for 15 min., and then were kept on a bed outside the sauna for additional 30 min. with sufficient warmth provided by blankets. ...Therapeutic benefit was demonstrated by regression of rest pain in all patients. Ischemic ulcers healed in all of the 7 limbs, resulting in successful limb salvage. ... In conclusion, we demonstrated that Waon therapy improved symptoms, status, and blood flow in patients with PAD."
Full article in the Journal of the American College of Cardiology
Efficacy of Waon therapy for fibromyalgia
Abstract: Fibromyalgia syndrome (FMS) is a chronic syndrome characterized by widespread pain with tenderness in specific areas. We examined the applicability of Waon therapy (soothing warmth of far infrared therapy) as a new method of pain treatment in patients with FMS. Thirteen female FMS patients received Waon therapy once per day for 2 or 5 days/week. The patients were placed in the supine or sitting position in a far infrared-ray dry sauna for 15 minutes, and then transferred to a room where they were covered with a blanket from the neck down to keep them warm for 30 minutes.
RESULTS: All patients experienced a significant reduction in pain by about half after the first session of Waon therapy (11-70%), and the effect of Waon therapy became stable (20-78%) after 10 treatments. Pain VAS and FIQ symptom scores were significantly (p<0.01) decreased after Waon therapy and remained low throughout the observation period.
CONCLUSION: Waon therapy is effective for the treatment of fibromyalgia syndrome.
Intern Med. 2008; 47(16):1473-6 (ISSN: 1349-7235) Matsushita K; Masuda A; Tei C The First Department of Internal Medicine, Kagoshima University Hospital.
Read the article online at MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. http://www.jstage.jst.go.jp/article/internalmedicine/47/16/47_1473/_article.
Beneficial Effects of Waon Therapy on Patients with Chronic Heart Failure
Background: We have reported that Waon therapy, the repeated use a dry sauna at 60°C, improves cardiac and vascular function in patients with chronic heart failure (CHF). We conducted a prospective multicenter case-control study to confirm the clinical efficacy and safety of Waon therapy on CHF at 10 participating hospitals. Methods: Patients (n=188) with CHF were enrolled and treated with standard therapy for at least one week, and then were randomized to a Waon therapy group (n=112) or a Control group (n=76). All patients continued conventional treatment for an additional two weeks. The Waon therapy group was treated with a far infrared-ray dry sauna at 60°C for 15 minutes and then kept on bed rest with a blanket for 30 minutes each day for 2 weeks. ... During the study, none of the patients treated with Waon therapy had worsened clinical symptoms. Conclusion: In this prospective multicenter study, we confirmed that Waon therapy is safe, improved clinical symptoms and cardiac function, and decreased cardiac size in CHF patients. Waon therapy is an innovative and promising therapy for patients with CHF.
Korean Study: Benefits of far infrared heat therapy for dysmenorrhea in high school girls
Hong, Department of Nursing, Chodang University, Muan, Korea
Thermotherapy using an infrared heating element was provided to high school girls.
RESULTS: The experimental group had significantly lower mean scores for menstrual pain, dysmenorrhea, and blood pressure than those in the control group. However, no significant differences were found between two groups for pulse, respiration, and temperature.
CONCLUSION: These findings show that thermotherapy was effective for reduction of menstrual pain, dysmenorrhea, and B/P. Therefore, this therapy could be used as a nursing intervention for students with dysmenorrhea.
Dr. Oz on the Oprah Show: High-Tech Ways to Extend Your Life
High-Tech Ways to Extend Your Life By Dr. Mehmet Oz The Oprah Winfrey Show | March 24, 2009.
From the Oprah.com website, accessed October 13, 2011
"The next life extension tool that Dr. Oz wheels onto Oprah's stage can help you burn 700 calories...without lifting a finger. Dr. Oz says his in-laws introduced him to the infrared sauna, which is slightly different than a normal sauna. 'It makes the same rays that come from the sun and filters out the UV radiation, so it only gives you the infrared radiation,' he says. 'That radiation that's infrared goes a little bit into your skin so, without heating you up and the external environment too much, it heats the body up.' After a few minutes in the sauna, Oprah says she's starting to feel the heat. Dr. Oz says the high temperature helps lower blood pressure and increase blood circulation. 'It gets your heart to beat faster, and it burns calories,' Dr. Oz says. 'It raises your metabolism a little bit, and also when you sweat, you sweat out toxins through the skin.'"
Therapeutic Effects of Infrared Therapy
in Lehmann, Williams, Wilkin
following information has been summarized from Chapter 9 of Therapeutic
Heat and Cold, Fourth Edition, Editors Justus F. Lehmann, MD,
Williams, and Wilkin, or concluded from data gathered there.
it is accepted that heat produces the following desirable therapeutic
Infrared heat increases the extensibility of collagen tissues. Tissues
heated to 45 degrees Celsius and then stretched exhibit a nonelastic
residual elongation of about 0.5 to 0.9 percent that persists after the
stretch is removed. This does not occur in these same tissues when
stretched at normal tissue temperature.
of tissue in the presence of heat would be especially valuable in working
with ligaments, joint capsules, tendons, fasciae, and synovium that have
become scarred, thickened, or contracted. Experiments cited clearly showed
low-force stretching could produce significant residual elongation when
heat is applied together with stretching or range of motion exercises.
Infrared heat decreases joint stiffness. There was a 20% decrease in
rheumatoid finger joint stiffness at 45 degrees Celsius (112'F)
as compared with 33 degrees Celsius (92'F)
which correlated perfectly to both subjective and objective observation of
stiffness. Speculation has it that any stiffened joint and thickened
connective tissues may respond in a similar fashion.
Infrared heat relieves muscle spasms. Muscle spasms have long been
observed to be reduced through the use of heat, be they secondary to
underlying skeletal, joint, or neuropathological conditions. This result
is possibly produced by the combined effect of heat on both primary and
secondary afferent nerves from spindle cells and from its effect on Golgi
Infrared heat treatment leads to pain relief. Pain may be relieved via the
reduction of attendant or secondary spasms. Pain is also at times related
to ischemia due to tension or spasm that can be improved by hyperthermia
that heat-induced vasodilation produces, thus breaking the feedback loop
in which ischemia leads to further spasm and then more pain. Heat has been
shown to reduce pain sensation by direct action on both free-nerve endings
in tissues and on peripheral nerves. In one dental study, repeated heat
applications led finally to abolishment of the whole nerve response
responsible for pain arising from dental pulp. Heat may lead to increased
endorphin production and a shutting down of the so-called "spinal
gate" of Melzack and Wall, each of which can reduce pain.
infrared therapy using lamps tuned to the 2 to 25 micron wave band is used
for the treatment and relief of pain by over 40 reputable Chinese medical
Infrared heat increases blood flow. Heating one area of the body produces
reflex-modulated vasodilators in distant-body areas, even in the absence
of a change in core temperature. Heat one extremity and the contralateral
extremity also dilates; heat a forearm and both lower extremities dilate.
muscles produces an increased blood flow level similar to that seen during
exercise. Temperature elevation also produces increased blood flow and
dilation directly in capillaries, arterioles, and venules, probably
through direct action on their smooth muscles. The release of bradykinin,
released as a consequence of sweat gland activity, also produces increased
blood flow and vasodilation.
body hyperthermia, with a consequent core temperature elevation, further
induces vasodilation via a hypothalamic-induced decrease in sympathetic
tone on the arteriovenous anastomoses. Vasodilation is also produced by
axonal reflexes that change vasomotor balance.
Infrared heat assists in resolution of inflammatory infiltrates, edema,
and exudates. Increased peripheral circulation provides the transport
needed to help evacuate edema, which can help inflammation, decrease pain,
and help speed healing.
Infrared heat introduced in cancer therapy. More recently, infrared heat
has been used in cancer therapy. This is a new experimental procedure that
shows great promise in some cases when used properly. American researchers
favor careful monitoring of the tumor temperature; whereas, the successes
reported in Japan make no mention of such precaution.
Infrared heat affects soft tissue injury. Infrared healing is now becoming
a leading edge care for soft tissue injuries to promote both relief in
chronic or intractable "permanent" cases, and accelerated
healing in newer injuries.
About Infrared Heat Effects on Blood Circulation
of the following ailments may be associated to some degree
with poor circulation and, thus may respond well to increased
peripheral dilation associated with infrared treatments:
Arthritis; Rheumatism; Sciatica; Strained muscles; Backache;
Fatigue; Hemorrhoids; Stretch Marks; Nervous Tension;
Menstrual Cramps; Children's
Overtired Muscles; Varicose Veins; Neuritis; Bursitis; Leg and
Decubitis ulcers (that fail to heal using conventional
approaches); Post-operative edema (treatment has proven so
effective, hospital stays were reduced by 25%); Peripheral
occlusive disease ('the
goal is to maintain an optimal blood flow rate to the affected
In general the temperature should be maintained at the highest
level, which does not increase the circulatory discrepancy as
shown by cyanosis and pain.'Therapeutic Heat and Cold, pp. 456-457).
yellowish or dull color on the back indicates poor blood
orange color of the middle and lower back indicates
red color indicates temperature rise and improved blood
Therapeutic Effects of Infrared Therapy
in Low & Reed
following information has been summarized from Chapter 7 of Electrotherapy Explained: Principles and Practice, Third Edition, by John Low, FCSP, DipTP, SRP and Ann Reed, MCSP, DipTP, SRP (Woburn, MA; Butterworth-Hainemann, 2001).
Physiological Effects of Temperature Changes on the Body Tissues:
Metabolism, being a series of chemical reactions, will increase with a rise of temperature. As with any chemical action, Metabolism is increased by a temperature rise. The actual change is about one-eighth (13%) for each 1oC so increasing the tissue temperature by, say, 4oC would increase the metabolic rate by some 60%. ... From a therapeutic point of view the local temperature changes that can, or should be achieved are limited in the deeper tissues to about 5 or 6oC above core temperature.
2. The resistance to flow in a blood vessel depends directly on the viscosity of the fluid, and raising the temperature lowers the viscosity. Viscosity changes affect not only the fluids in narrow vessels (blood and lymph), but also fluid movement within and throughout the tissue spaces.
3. Collagenous tissue extensibility has been shown (Lehmann et al., 1970) to increase within a therapeutically applicable range (40 - 45oC). Joint stiffness has been found to be reduced by heating (Wright and Johns, 1961); on cooling, joint stiffness is increased.
4. Blood vessels are changed during heating. Vasodilation occurs not only to distribute additional heat around the body, allowing compensatory heat loss from regions not heated, but also to protect the heated skin. Vasodilation due to heat is caused by: a) a direct effect on capillaries, arterioles and venules, causing them all to dilate (Lehmann and de Lateur, 1982); the nature of this process is not understood; b) an axon reflex; c) greater acidity of heated tissues from carbon dioxide and lactic acid released at a higher rate due to increased metabolism; d) an inflammatory reaction due to damaged proteins caused by heating.
5. Because of all the foregoing, there is an inevitable increase in fluid exchange across capillary walls and cell membranes. The acidity of the blood rises, and both carbon dioxide and oxygen tensions increase. There is an increase in lymph formation and a higher blood leucocyte count.
Therapeutic Effects of Local Tissue Heating:
Encouragement of Healing
Any condition in which increased metabolic rate, cell activity and local blood flow are beneficial can be appropriately treated by mild heating.
Chronic Inflammatory states and the stages of repair and regeneration are all appropriately treated with mild heating. All forms of therapeutic heating are applied to a wide range of chronic and post-traumatic conditions including arthroses, soft tissue lesions and post-surgical healing.
2. Control of Some Infections
Dry surface heating, achieved by infrared radiation or hot air, may have a particular role in the control of surface infections, such as chronic paronychia, a fungal (candida) infection, or other infections. Surface drying will diminish bacterial colonization.
3. Relief of Pain
Surveys of patients with persistent pain have found that some form of heat ranks highly, after analgesia, among the measures used by patients to control pain. For example, Barbour et al. (1986) found that heat was the most effective non-analgesic method of pain control for 68% of the cancer outpatients in their sample.
The stimulation of sensory heat receptors may activate the pain gate mechanism. Cervero et al., 1993, suggest that the development of hyperalgesia as a consequence of mild heating may contribute to pain modulation.
The sympathetic skin response to pain was found to be reduced by therapeutic heat applied in a distant region (Yagiz On et al., 1997.) The authors suggest that this clear analgesic effect of heating may be due to suppression of cortical pain as a consequence of increased levels of endorphins and possibly due to local inhibition of both afferent and efferent C fibers.
Vascular changes could also reduce local pain, as blood flow "washes out" some pain provoking metabolites resulting from tissue injury, including prostaglandins and bradykinin (Lehmann and Letour, 1982; Wadsworth and Chanmugan, 1980.)
Other mechanisms that may account for pain relief include the reduction of muscle spasm, the sedative effect, and a decrease in sympathetic nervous system activity which is said to promote vasodilation in deeper blood vessels (Michlovitz, 1986.)
4. Reduction of Muscle Spasm
Investigated by Lehmann and de Lateur, 1982. Since pain and muscle spasm are interdependent, a reduction in one will cause a reduction in the other.
5. Sedative Effect
The sedative effect of superficial heat could be a reflex phenomenon due to rise in skin temperature itself, or a consequence of pain relief (Lehmann and de Lateur, 1982.)
The use of heat for pain relief is primarily based on empirical observation and the underlying mechanisms are unknown (Michlovitz, 1986.)
6. Increase of Range of Joint Motion
There seem to be three mechanisms involved here:
Analgesic effects allowing greater tolerance of stretching (Michlovitz, 1986)
Reduction in viscosity of tissues (Wright and Johns, 1961)
Increased collagen extensibility at higher temperature (Lehmann et al., 1970)
Therapeutic Effects of Sauna Therapy
Sauna as a Valuable Clinical Tool for Cardiovascular, Autoimmune, Toxicant induced and other Chronic Health Problems by Walter J. Crinnion, ND (accessed online October, 2011 at AMR, Alternative Medicine Review)
Abstract: Sauna therapy has been used for hundreds of years in the Scandinavian region as a standard health activity. Studies document the e!effectiveness of sauna therapy for persons with hypertension, congestive heart failure, and for post-myocardial infarction care. Some individuals with chronic obstructive pulmonary disease (COPD), chronic fatigue, chronic pain, or addictions also can benefit. Existing evidence supports the use of saunas as a component of depuration (purification or cleansing) protocols for environmentally-induced illness). While far-infrared saunas have been used in many cardiovascular studies, all studies applying sauna for depuration have utilized saunas with radiant heating units. Overall, regular sauna therapy (either radiant heat or far-infrared units) appears to be safe and offers multiple health benefits to regular users. One potential area of concern is sauna use in early pregnancy because of evidence suggesting that hyperthermia might be teratogenic. (Altern Med Rev 2011;16(3):215-225)