The following claims are not supported by medical evidence. These are claims from far-infrared sauna manufacturers, and customers. 
Detoxification Claimed to stimulate the body to release fat-soluble toxins, heavy metals, and other toxic chemicals in sweat via pores more effectively than any other form of heat therapy or exercise.

Sweating via exercise is said not to be as effective because it works via the sympathetic nervous system which is said to inhibit toxin elimination.
Reported to be “method of choice” for chronically ill patients as well as those that are well and wish to stay that way by reducing their “toxic burden. ”This is the only way to remove the noxious substances that silicone breast implants put out.
Reports have been made that it can relieve the symptoms of drug-induced lupus.
The list of chemicals claimed to be removed from the body includes:  Mercury, lead, copper, cadmium, manganese, sodium, chloride, arsenic, nickel, benzenes, street drugs, prescription drugs, anaesthetics, cholesterol, urea, nicotine, sulphuric acid

Immune System Enhancement A typical sauna session will cause a brief 1 to 3 degree F increase in body temperature.  Fever is the body's defence against bacteria, microbes and consequent infection.  This side effect is said to trigger the production of white blood cells by the bone marrow and killer T cells by the thymus.  The overall result is claimed to be immune system enhancement as well as the killing of microorganisms.
Stress Continuous strain on the autonomic nervous system leads to a high level of stress, one of the elusive causes of many chronic diseases.  Allowing the capillaries to dilate may improve circulation, thus stress levels are reduced.

Weight Control Although weight loss from perspiration is quickly regained, sending more blood to the capillaries and converting fats results in as much as 600 calories during one session.  If heavy metals are reduced, this will correct metabolic imbalances that were causing poor digestion and weight gain.  Also, toxins stored in fat are decreased making it easier for weight loss. 

Some proponents claim that a 15 minute sauna session is as effective for weight loss as rowing or jogging for 30 minutes.
The improved blood flow to organs and endocrine glands speeds up their metabolic process, increasing caloric burn.
Because fat becomes water soluble at 110 degrees F, subcutaneous fat can be released along with the sweat and toxins

Skin Cleansing and Rejuvenation Claims to open clogged pores allowing for removal of dirt, oil, and makeup.  In addition, there are improvements in skin problems such as acne, rashes, burns, eczema and psoriasis.  Scars, even keloids, may be gradually softened

Cardiovascular Conditioning The body responds to the deep heating effect via a hypothalamic-induced increase in both heart volume and rate. This beneficial heart stress leads to a sought after cardiovascular training and conditioning effect, including lowering blood pressure. The human body will naturally try and cool itself as temperature increases.  It does this by diverting blood from internal organs to the extremities and skin by vasodilatation.  This increases heart rate, cardiac output and metabolic rate. Claims are made that it can take the place of exercise for patients undergoing cardiac rehab, with arthritis, allergies, skin conditions, and other painful conditions. Claims to sweat the equivalent of running 2-6 m

Pain Relief and Control
Claims to eliminate or reduce the pain of arthritis, muscle spasms, shoulder pain, neck and back pain, sprains of any area, and reduce scar tissue and adhesions.  Will rapidly increase the healing process in any non-acute injury.Increased secretions of:

• ACTH
• GH
• Endorphins
• LH/FSH
• Prolactin
• Renin-Angiotensin, Aldosterone ,Musculoskeletal
• Claim to have seen improvements in:
• Arthritis (gouty, rheumatoid and DJD)
• Shoulder pain
• Bursitis
• Post-exercise muscle pain
• Muscle tension
• Healing of sprains and strains more quickly
• Spinal cord shock
• AdhesionsLow back pain
  
• Muscle spasms
• Cancer Therapy

Some supporters of sauna therapy state that “hyperthermia is a well-researched therapy for cancer.”  They state that the high temperatures can “select” for abnormal cells and that tumours are unable to handle the high heat.