Taking the Cold Plunge

Most people have seen videos on the news or in social media feeds showing groups of people taking the “polar bear plunge” or watching an individual start their day by sitting in an ice bath or in a frozen lake, stating that it improves their overall health and wellness. But is this type of cold immersion therapy really good for your health? And is it safe?

What is Cold-Water Immersion Therapy?

Cold-water immersion (CWI) therapy is the process of submerging the body or a particular joint in an ice bath typically around 59°F. It is commonly used among athletes to help reduce muscle soreness and cool the body down after intense exercise or competition.

According to the National Institutes of Health, the potential benefits of CWI date as far back as 3500 BC, when the ancient Greeks used it as a form of relaxation and socialization. More documented instances of CWI being used for medicinal and analgesic purposes, including fever treatment, have been found as time progressed. Philosophers, researchers, and physicians have been experimenting with CWI for centuries to document its potential benefits to human health.

Additional benefits of CWI have been suggested to include boosting the immune system, enhancing peripheral circulation, increasing libido, and burning calories. CWI has also been hypothesized to benefit mental health treatments, including potentially reducing stress, anxiety, and depression symptoms. A 2018 case report published in BMJ Case Reports outlines the successful use of weekly cold, open-water swimming to treat a 24-year-old woman with major depressive disorder. The report shows that the woman was able to use cold water swimming to become completely medication-free and continue without medications at the one-year follow-up.

Unfortunately, strong scientific research documenting real support for the benefits of CWI therapy is lacking. According to an article in the International Journal of Circumpolar Health, “many of the proclaimed benefits are based on subjective claims and anecdotal cases.”

So why is CWI becoming more and more popular outside of competitive athletes?

Extreme Cold Training

In 2011, a Dutch extreme athlete with no medical education or training named Wim Hof gained notoriety for his unusual training techniques. Hof, who received the nickname “The Iceman,” began breaking numerous records relating to cold exposure, such as climbing Mt. Kilimanjaro in shorts and running a half marathon above the Artic Circle barefoot.

Hof, who holds a 21 Guinness World Records, including one for swimming under ice, began incorporating his own form of CWI into his training techniques to withstand extreme temperatures and help control his breathing, heart rate, and blood circulation. His personal motto of “what I am capable of, everybody can learn” has led him to develop and share the Wim Hof Method®, which goes beyond traditional CWI to incorporate breathing and meditating techniques.

The Wim Hof Method’s three pillars are:

Breathing exercises. Hof has developed special breathing exercises which he describes as “controlled hyperventilation or power breathing.” According to Hof, the goal of these breathing exercises combined with meditation is to release more energy, influencing the nervous system and changing several physiological responses.

Cold therapy. Hof suggests that proper and frequent cold exposure can lead to overall health benefits, including “the buildup of brown adipose tissue and resultant fat loss, reduced inflammation that facilitates a fortified immune system, balanced hormone levels, improved sleep quality, and the production of endorphins.”

Commitment. This pillar is considered the foundation of the other two. It requires patience and willpower to master conscious breathing and cold exposure. According to Hof, “If you really want to become a better version of yourself, then increasing willpower is one of the most essential things to do.”

In recent years, many celebrities, such as Gwyneth Paltrow and Harry Styles, as well as ice bath companies and cold therapy retreats, such as Blue Cube and Remedy Place in New York and Los Angeles, are also jumping on the extreme cold health trend made popular by Hof.

The Science

Studies based on Hof’s three pillars and methodology began in 2007 and are ongoing to date. The early studies were conducted on Hof himself to gauge how he was able to train his body to adapt to cold exposure and influence his own nervous system.

Additional research has been conducted in the form of proof-of-concept study designs, such as a 2016 study published in Clinical Rheumatology, which showed positive impacts in symptom reduction for arthritis; however, larger clinical studies are recommended to assess the validity and help confirm the results.

More recent research has continued to focus on the body’s inflammatory response. A 2022 pilot study published in the American Psychosomatic Society showed that cold exposure training and breathing exercises increased plasma epinephrine levels, enhanced anti-inflammatory levels, and attenuated proinflammatory cytokine levels in a group of healthy men. The basis of the study was to show that the immunomodulatory effects of this intervention could be replicated to help pave the way for clinical trials.

In a 2023 article published in Current Psychology, the effects of the Wim Hof Method were evaluated on perceived stress. Researchers indicated that the combination of breathing and cold therapy techniques “may be employed to decrease [an] individual’s perceived stress.” Another study is currently being conducted at the University of California at San Francisco to further evaluate the impact of the Wim Hof Method on mental health and stress resilience.

As research on the validity of the Wim Hof Method and CWI therapy continues, there are concerns about employing this methodology.

The Dangers of CWI Therapies

According to the National Center for Cold Water Safety (NCCWS), water temperatures between 50°F and 60°F “can kill you in less than a minute.” This is not because of hypothermia but cold shock—an involuntary response that can cause gasping—and swimming failure. Cold shock can be specifically dangerous when the head is submerged underwater, and involuntary gasping occurs, causing the water to fill the lungs and the individual to drown.

NCCWS and the American Heart Association also state that cold shock can cause heart failure and/or stroke. This can occur because CWI causes an immediate, massive increase in heart rate and blood pressure. Their risk may be increased in some individuals, especially those already vulnerable with arrhythmias or blood pressure conditions.

The polar plunges that are covered on the news and/or social media sites depict masses of people running into icy waters to dip into the freezing temperatures. What isn’t shown is the medical staff standing by to assist individuals who experience cold shock, whether rescuing them from the water or providing treatment on land. Even though a person makes it out of the water, the cooled blood in their arms and legs will return that chilled blood to the heart, potentially causing an instant drop in blood pressure that requires immediate intervention.

While the Wim Hof Method attempts to counteract the risk of cold shock by teaching breathing techniques to help control the gasp reflex caused by sudden cold temperatures, the risks remain. According to investigative journalist and anthropologist Scott Carney, there have been 13 deaths linked to the Wim Hof Method, including that of a 17-year-old girl, which has sparked a major lawsuit.

Key Takeaways

Although there are thousands of years of documented cases of CWI as potentially beneficial for a myriad of conditions, modern-day medical science is still in disagreement. Long-term clinical trials are necessary to prove the safety and efficacy of CWI as a valid therapeutic practice.

As the controversy surrounding the benefits and risks of cold immersion therapy continues, it is important to note that none of the methods discussed support instantaneous acclimation to the cold. The process of acclimatizing must be undergone to allow the body to assimilate to longer periods of cold exposure. The risk of cold shock must be monitored closely at every stage of cold adaptation.

While CWI and other cold plunge health trends offer some attractive promises of potential health benefits, the one steadfast process of integrating these therapies into a wellness plan is to begin by consulting a healthcare practitioner. Monitoring and guidance from a healthcare professional can assist in identifying potential risks that can vary from person to person.