Symptoms of depression, fatigue, pain, and loss of appetite are often associated with cancer and cancer treatments and can significantly worsen quality of life of patients. A number of studies published in the last five decades suggest that brief cooling of the body can reduce pain and fatigue and improve mood and appetite in healthy subjects and in some groups of patients. Possible physiological mechanisms of these effects are discussed at length in this document. Repeated moderate cooling (e.g., adapted cold showers) could improve several components of quality of life, although the effectiveness of this approach in cancer patients has not been evaluated. Moderately cold hydrotherapy is safe for the vast majority of people and may allow a patient to undergo more rounds of chemo-, radiotherapy, and/or surgical treatment because cold hydrotherapy can reduce their side effects. Methodological details and potential practical difficulties are discussed in the text.