What Happens to Your Body When You Do Cold Plunges

Taking the plunge takes on fresh new meaning when it’s into frigid waters. While the idea of dipping into wintry waters may disturb your thermal comfort, many people subscribe to polar-bear-like behavior in the name of health. And the cold, hard evidence has been trending on your social feeds, where athletes and influencers document their icy water-bath challenges. Submerging into water at teeth-chattering temperatures is a popular practice for reducing post-workout muscle pain, inflammation and stress. But is it worth the hype (or possible hypothermia)? We’ll dive into the benefits and risks of cold water immersion, known as cold plunges, ice baths and the like.

Related: The Best Shower Temperature for Health, According to Dermatologists

What Is a Cold Plunge?

​According to a 2022 review published in the European Journal of Applied Physiology, cryotherapy is an umbrella term for therapeutic practices involving the use of cold water, ice or air. Cold plunging, a type of cryotherapy, happens when you immerse your body in cold water at varying temperatures and durations. Exposure to these bone-chilling temps removes body heat, drops internal temperatures and changes blood flow. Cold water immersion (CWI), another way to talk about ice baths, cold baths or cold plunges, isn’t anything new; it dates back to 3500 B.C., per the 2022 review. Turns out, Hippocrates felt strongly about cold for medicinal therapy, and some credit him as the grandfather of cryotherapy. So, how cold are we talking? “The normal temperature range for most cold water plunges is between 55 and 69 degrees Fahrenheit,” says Raj Dasgupta, M.D., FACP, FCCP, FAASM, chief medical advisor for Sleep Advisor.

How far into the water you go is up to you. The most daring plungers may briefly soak their entire bodies, while others may opt for a partial up-to-the-neck or chest drenching. Though there are different methods to complete your icy plunge, one thing remains the same. For the most part, no one takes the icy bath just for kicks and giggles. Many will decide to drop into frigid waters to reap potential health benefits.

Benefits of Cold Plunges

You May Decrease Inflammation and Improve Immunity

Inflammation is inevitable, and while it often has a sour reputation, it’s normal. “Inflammation is the body’s natural response to an injury or an infection, but when it’s chronic, it can lead to health problems such as heart disease,” says Dasgupta. Cold temperatures could benefit inflammation by acting on your blood vessels. “Ice baths can help constrict blood vessels and reduce blood flow to affected areas. After your blood vessels constrict and blood flow decreases, the healing begins once you get out. Since your vessels were narrowed, your body’s natural reaction is to push blood back to the areas as fast as possible,” says Dasgupta. A 2022 randomized control study published in Biological Research for Nursing found significant pain reduction in people with gout arthritis, an inflammatory condition. “Cold therapy alleviates pain by reducing inflammation but also interferes with your brain’s perception of the pain. A classic example is getting a cold spray before an injection; it works by dulling the pain sensation that travels through your nerves,” says Dasgupta. Since the immune system largely regulates inflammation, cold plunges may benefit immunity, too. “Cold-water exposure can increase the production of white blood cells in the body, which are responsible for fighting infection,” says Dasgupta.

You Could Increase Your Circulation

Your heart, capillaries, veins and arteries comprise your circulatory system, facilitating blood flow to the whole body. “The working hypothesis is that the ice water stresses and strains your body, and it goes into survival mode, working hard to maintain its core body temperature. This stimulates your body to increase blood flow and improve circulation in order to help deliver oxygen and nutrients to areas of the body that need to recover,” says Dasgupta.

You Might Boost Your Mood

Imagine dunking into chilly waters and coming out feeling alert, proud and inspired, with less distress and nervousness. In fact, that’s what happened in a small 2023 study published in Biology researching adults immersed in 68°F water for five minutes. Emotional conditions such as anxiety and depression may be linked to lower levels of neurotransmitters, chemical messengers that help keep your brain well-functioning. But when the body endures cold, it triggers neurotransmitters that help regulate emotions and stress. “Some speculate that an increase in these mood-regulating brain chemicals, like dopamine, may explain the post-plunge “high” people feel following a cold soak,” says Dasgupta.

Stress is an inevitable part of life, but cold plunges may offer some relief. “Some believe that an ice-water face immersion can activate the parasympathetic nervous system, which prompts the body to relax after a stressful event. Researchers also hypothesize that adapting to the shock of an ice-water plunge may improve a person’s ability to cope with other stresses,” says Dasgupta. The good news is, that it could take just one time to notice enhancements to your mood if frequent cold plunging isn’t your goal. In a small 2021 study published in Lifestyle Medicine, a one-time 20-minute plunge in 56°F water helped participants experience less negative mood disturbance and more vigor. However, according to Dasgupta, the research on ice-bath therapy for mental health conditions such as depression is limited.

You May Up Your Metabolism

Chilly temperatures trigger shivering, which is the body’s way of trying to warm up through continuous skeletal muscle contractions. Shivering allows your body to produce heat five times greater than what you can accomplish at rest. Further, CWI shivers can produce more heat than exercise because you’re not exerting as much energy. According to a 2022 review in the International Journal of Circumpolar Health, the increased muscle activity of shivering causes a rise in metabolic rate, helping you to burn more calories at rest. Moreover, under cold stress, blood flows to your brown adipose tissue.“The tissue in brown fat helps to burn calories, so regular exposure to cold temps might be able to help you lose weight,” says Josh York, CPT, founder & CEO of GymGuyz. Still, more research is needed on CWI and metabolic health to bolster research findings further.

You May Experience Less Post-Workout Muscle Soreness

Post-workout muscle soreness can make your subsequent workout a real pain. Many athletes turn to cold-water baths to prevent muscle soreness and stiffness and improve recovery. According to a 2023 review published in Sports Medicine, participants who used CWI significantly lowered creatinine-kinase levels, markers of muscle damage and delayed onset muscle soreness after high-intensity exercise, as compared to subjects who used passive recovery. Yet, these results were only in the short term. Lower water temperatures and short immersion times seemed to make the baths more effective. Results were similar in a 2021 review published in Physical Therapy, where CWI reduced pain in delayed onset muscle soreness after exercise.

How Do You Do a Cold Plunge and How Long Should It Last?

When starting out, consider focusing on cool temperatures versus icy waters. “People who want to try ice baths should start with 5 to 10 minutes in cool water, not ice water, and gradually increase the duration,” says Dasgupta. Multiple studies have found that short to medium immersion times, 5 to 15 minutes, have yielded favorable results, per a 2022 systematic review in Sports Medicine.

“It’s important to drink plenty of fluids before, during and after the bath, and take a hot shower or bath afterward to warm up,” says Dasgupta.

Potential Risks

Hypothermia

Cold plunges might seem cool, but they aren’t without risk. According to a 2022 article published by the American Heart Association, water removes heat from the body 25 times quicker than air. Even in water that appears to be not-so-cold, hypothermia can still happen in temperatures lower than 70°F, per the Centers for Disease Control and Prevention. What’s more, your body’s function begins to drop with the temperatures, and hypothermia starts to interfere with movement and thinking skills, posing great danger. Shivering, bluing of the skin and loss of consciousness are associated with hypothermia.

Cold Shock and Drowning

Cold shock is your body’s way of responding to rapid decreases in skin temperature, often causing an involuntary gasp. According to the 2021 study mentioned above, following the gasp response is hyperventilation, which could lead to inhaling water into the lungs and drowning. In combination, these events cause cardiovascular strain that makes the heart work harder.

Who Should Avoid Cold Plunges?

Individuals with Heart Conditions

No matter how determined, resilient or athletic you might be, cold plunges aren’t for everyone. According to a 2022 survey published in the Interactive Journal of Medical Research, cold-water swimming may put people with underlying heart and cardiovascular conditions at greater risk for poor heart health. The National Center for Cold Water Safety, a nonprofit organization, states that it only takes seconds for the fatal effects of cold-water submersion to set in. The AHA strongly cautions against these activities for these groups because they can cause the heart to work harder and result in death.

Older Adults

Growing older may call for additional layers of clothing to keep warm. According to MedlinePlus, getting older causes fat under the skin to decrease, making it more difficult to maintain body temperature. Hypothermia is one leading cause of death for older adults, per a 2022 article in the International Journal of Circumpolar Health. If you’re an older adult, you can protect your health by avoiding icy-water baths and talking to your medical provider about safe alternatives.

The Bottom Line

Though more research is necessary to prove the potential effects of ice-water baths on health, they could be worth the challenge in healthy individuals. But people with heart conditions and older people should speak with a medical provider before doing any immersive cold-water activity. If you’re planning to try CWI, be mindful of your health. “Listen to your body and get out of the bath if you start to feel dizzy, lightheaded or have any other problems,” says Dasgupta.