We don’t know what your specific circumstances are, so our comments will deal with the topic generally. The chilling truth is that cold immersion baths and showers do indeed have beneficial, physiologic effects in people who are otherwise well and in persons who have specific health or medical conditions. Additionally, studies involving cold immersion suggest that the regular, habitual practice may reduce the risk of developing some diseases.
In general terms, cold immersion, or “cold hydrotherapy” (CH), can be invigorating and improve mood, alertness, mental clarity, and resilience to stress as the body adapts. It is part of the practical, natural home treatments used by Adventists since Battle Creek days. Surprising new evidence suggests that cold immersion may be an epigenetic trigger that activates genes involved in immunologic and inflammatory processes, the development and function of brown fat, and the expression of heat shock proteins, which protect cells from stress and damage.
Brown fat (BF) is a type of fatty tissue that helps regulate body temperature by burning calories, in contrast to white fat (WF), the common type of fat associated with overweight and obesity, which stores excess calories. Men exposed daily for just two hours to cold immersion (lower than 60°F) for six weeks can increase the calorie-burning BF and increase the energy expenditure (fat burning) of WF. Cold hydrotherapy (CH) may also increase the metabolic rate and improve your body’s sensitivity to insulin depending upon the degree and duration of exposure, your body composition, and your health status. Additionally, CH can increase glucose uptake in skeletal muscle and therefore potentially provide some benefit for people with metabolic syndrome, type 2 diabetes, and hypertension.
The potential benefits don’t stop there. CH’s immunologic and anti-inflammatory effects may decrease the chronic pain of fibromyalgia and the fatigue of multiple sclerosis. It stimulates T lymphocyte and natural killer cell production and, along with its modulating effect on the heat shock proteins and its antioxidant stimulation, may be helpful in combating viral infections, including COVID-19. These effects also help explain the reduction of inflammation and muscle recovery seen in athletes after workouts and injuries.* The downsides of CH are few, but many people don’t usually equate “cold” with “comfort,” and some individuals may get really stressed even thinking of cold-water immersion, especially those who are not accustomed to cold exposure or who have a fear of cold water. Elderly persons and those with heart disease, hypothyroidism, or diabetes may be vulnerable to hypothermia (low body temperature), and CH may irritate sensitive skin or produce excessive dryness. Gradually acclimating to cold water is relatively easy if you are consistent and persistent. It is usually well tolerated, but check with your doctor to be sure you are not putting yourself at undue risk because of your specific situation.
*For further reading, see M.J.W. Hanssen et al., in Nature Medicine 21, no. 8 (August 2015): 863-865, doi:10.1038/nm.3891; R. J. Brychta and K. Y. Chen, in European Journal of Clinical Nutrition 71, no. 3 (March 2017): 345-352, doi: 10.1038/ejcn.2016.223.