Hyperthermia therapy is a type of medical treatment in which body tissue is exposed to slightly higher temperatures to damage and kill cancer cells or to make cancer cells more sensitive to the effects of radiation and certain anti-cancer drugs. When combined with radiation therapy, it is called thermoradiotherapy. Whole-body hyperthermia has also been found to be helpful for depression.

Local hyperthermia has shown to be effective when combined with chemotherapy or radiation therapy for cancers such as breast, cervical, prostate, head and neck, melanoma, soft-tissue sarcoma and rectal cancer, among others. Whole-body hyperthermia is generally considered to be a promising experimental cancer treatment, but requires close medical monitoring of the patient, as side effects can be serious.

Hyperthermia is considered the "fourth leg" of cancer treatment. It was historically was reserved for the most severe or recurrent cases of cancer. However, there is more evidence to support its use as a primary treatment. Hyperthermia is most effective when used alongside other therapies, so it is almost always used as an adjuvant therapy.