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Heat Therapy

Heat therapy as an alternative practice is different from hyperthermia, which is being tested in conventional clinical trials for treatment of cancer. Both types of heat therapy are discussed here.

Other common name(s): hyperthermia, heat treatment, thermotherapy, thermal therapy

Scientific/medical name(s): none


Heat therapy involves exposing part or all of the body to high temperatures. In cancer treatment, it is used mainly usually to enhance other forms of therapy, such as radiation and chemotherapy. Heat may be applied to affected parts of the body along with other treatments to help relieve certain kinds of pain or infections. Heat therapy may also involve injecting substances to cause a fever, such as DNP (chemical name 2-4-dinitrophenol) (see our document, Coley Toxins).


Local and regional heat therapy is being studied as a possible part of standard treatment for some cancers. Clinical trials are studying its use alone and along with radiation therapy and chemotherapy. More research is still needed to determine the full benefits of heat therapy in cancer treatment.

Heat can be used in different forms to help relieve joint or muscle pain due to arthritis, injury, or inflammation. It is also used as part of treatment for certain kinds of infections that are close to the body's surface, such as skin infections, generally along with antibiotics.

The use of heat therapy for cancer treatment that is not based on results of controlled clinical trials or is not investigational (currently being tested in carefully designed clinical trials) is generally considered an alternative treatment.

There are some serious complications linked to so-called whole-body heat therapy. The injection of unproven substances such as DNP to cause "intracellular hyperthermia" (see below) and fever has caused deaths. Available scientific evidence has not supported claims that this is a useful treatment for cancer.

How is it promoted for use?

Proponents of the alternative use of heat therapy claim that it reduces or even eliminates the need for conventional treatment. They say it decreases the number of invading organisms so the immune system can handle them, acting much like a fever helping the body fight off disease.

There is also an unproven treatment called intracellular hyperthermia, which is based on the theory that injection of DNP into the body heats cells from the inside out. Available scientific evidence does not support these claims. The injected substance is known to be dangerous and has caused deaths.

Certain types of heat therapy are being tested in conventional cancer treatment and may be promoted for helping chemo or radiation to work better.

What does it involve?

External heating in complementary or alternative therapy may involve hot water, warming blankets, warm compresses or hot pads, hot wax, heated chambers, or other methods to heat all or part of the body. This may be done along with other types of alternative or complementary treatment.

Internal heating using intracellular hyperthermia is an alternative therapy that involves injecting DNP into the body to produce fever. It may be used along with other types of treatment in nontraditional treatment settings.

Three major types of heat therapy are being investigated by cancer researchers in mainstream medicine: local, regional, and whole-body. In standard medical care, there is some evidence that local and regional heat therapy may help slow or stop cancer growth.

  • Local heat therapy involves applying fairly high heat to a very small area, such as a tumor. The area may be heated from the outside using high-frequency waves, or from the inside using sterile probes (thin, heated wires or implanted microwave antennae) or radiofrequency electrodes. The temperature of the tumor is high enough to quickly kill its cells. Another form of local heat therapy involves raising the temperature of an affected area just a few degrees to improve blood flow so that chemo or radiation work better.
  • In regional heat therapy, an organ or limb is heated. One method, called perfusion, involves removing the patient's blood, heating it, and then pumping it into a region to heat that part of the body from the inside.
  • Whole-body heat therapy is being studied for treating metastatic cancer (cancer that has spread). It involves the use of warm blankets, warm water, inductive coils (like those used in electric blankets), or thermal chambers (much like large incubators).

Heat is sometimes applied to the outside of the body to help relieve stiffness and pain from arthritis or other muscle and joint problems. This may involve warm compresses, warm baths, melted wax, or other techniques. Heat is sometimes used with conventional therapy to help treat certain skin infections or inflammation. Warm soaks, warm compresses, and other means may be used to heat the affected area. Some of these methods are used in treatment centers, while others can be used at home.

What is the history behind it?

The first documented use of heat treatment dates back to 400 BC with Hippocrates. In 500 BC, the Greek physician Parmenides believed that if he could create fever, he could cure all illness. In India, heat was used to treat breast cancer more than a thousand years before that.

More recent scientific interest in heat therapy began in 1866, when M. Busch, a German physician, described a patient with a neck sarcoma which disappeared after a prolonged high fever. Similar reports were made by others 20 years later. In 1893, William Coley gave patients toxins extracted from Streptococcus pyogenes and Serratia marcescens bacteria to cause fever. In 1898, the Swedish gynecologist F. Westermark published a study in which he described using a coil containing hot water as a source of local heat to treat 7 women with cancer of the cervix. The treatment was painful, but one cancer reportedly disappeared and others seemed to improve. Reports followed of tumors responding to both localized and whole-body heat therapy treatments. But the scientific evidence was weak and interest soon faded.

In the 1960s, a series of biochemical studies involving the effects of high temperature on normal and malignant cells were conducted using rodent cells. Based on their observations, researchers concluded that cancer cells were more sensitive to heat than normal cells. However, studies have since shown that there is little or no difference between cancer cells and normal cells in terms of their response to heat alone.

What is the evidence?

In a technique called radiofrequency ablation, very high temperatures can be used to kill cancer cells directly, but the heat is carefully controlled and precisely targeted to reduce damage to normal tissues nearby. Radiofrequency ablation uses much higher temperatures than hyperthermia or heat treatment, and uses electrodes to heat and destroy the cancer.

The temperatures normally used for hyperthermia (up to 113º F) are usually not hot enough to kill cancer cells outright unless used along with radiation therapy or chemotherapy. Many laboratory and clinical studies have shown that heat therapy can help radiation therapy in local and regional tumor control. It can also make some types of chemotherapy work better in certain cancer cases. Whole-body heat therapy is currently being studied as a method to treat illnesses that are spread throughout the body.

More research is underway on different types of chemotherapy that can be used along with local and regional heat therapy as well as whole body heat therapy. While hyperthermia is a promising way to improve cancer treatment, it is largely an experimental technique at this time and is not commonly used. Clinical trials of hyperthermia are now being done to try to find the best way to use this technique. Current studies are looking at its usefulness in treating many types of cancer (see our document, Hyperthermia).

Local heat is also applied to certain areas of the body in conventional medicine. It has been shown in clinical studies to help relieve symptoms such as arthritis pain for a short time. Its use with other medical conditions, such as small skin infections, may help speed healing.

Available evidence for DNP and other alternative substances that are injected to induce fever do not support claims that it can treat cancer or other illness. There is, however, evidence that some of these treatments have caused harm or death.

Are there any possible problems or complications?

Heat therapy can cause or worsen internal bleeding. The high death rate and labor-intensive methods associated with whole-body heat therapy have also caused concerns. Heat therapy as part of cancer treatment should only be given under careful supervision by expert doctors. Most normal tissues are not harmed during conventional medical hyperthermia if the temperature stays below 111 to 113° F. However, the heat can be uneven, and some areas of the body can be exposed to greater heat, resulting in burns, blisters, or pain.

Heat should be used with caution in people who have anemia, heart disease, diabetes, seizure disorders, or tuberculosis, as well as women who are pregnant, and people who are sensitive to the effects of heat.

Hot compresses or soaks used to help treat skin infections can spread germs to others if the container or compress is not thoroughly cleaned after use. Talk with your doctor about how to best protect others if heat is recommended for an infection.

"Intracellular hyperthermia" using DNP has caused a number of deaths. DNP has long been banned by the FDA because of this.

Relying on this type of treatment alone and avoiding or delaying conventional medical care for cancer, may have serious health consequences.

For more information

More information from your American Cancer Society

The following information on complementary and alternative therapies may also be helpful to you. These materials may be found on our Web site (www.cancer.org) or ordered from our toll-free number (1-800-227-2345).

Coley Toxins


Dietary Supplements: What Is Safe?

The ACS Operational Statement on Complementary and Alternative Methods of Cancer Management

Complementary and Alternative Methods and Cancer

Placebo Effect

Learning About New Ways to Treat Cancer

Learning About New Ways to Prevent Cancer


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Note: This information may not cover all possible claims, uses, actions, precautions, side effects or interactions. It is not intended as medical advice, and should not be relied upon as a substitute for consultation with your doctor, who is familiar with your medical situation.

Last Medical Review: 03/07/2011
Last Revised: 03/07/2011