What Is Cold Water Therapy? A Detailed Scientific Guide

Stepping into an ice-cold shower may seem like a rough way to start the day, but some research suggests it could benefit your health.

Known as cold water immersion, or cold water therapy, the practice — which can also take the form of ice baths or polar plunges — is a complementary therapy that proponents say can alleviate pain, accelerate post-workout recovery, and boost mood, among other potential perks.

Here's a look at what cold water therapy entails, whether it's safe for you, and how to get started.

Cold water therapy, a combination of cryo- (cold) and hydro- (water) therapy, is an age-old practice with origins in the Greco-Roman era. The practice is intended to reduce discomfort and promote good health.

Immersing yourself in cold water may affect the body through a few different mechanisms:

Vasoconstriction When you're cold, your blood vessels constrict, or narrow. This process, known as vasoconstriction, may help reduce inflammation.
Hydrostatic Pressure The gentle pressure water exerts on your body (known as hydrostatic pressure) similarly reduces pain and swelling, while boosting blood flow to the heart, says Sean Carpenter, DPT, a physical therapist with Memorial Hermann Health System in Houston.
“It's like a natural compression system for your muscles,” Carpenter says.
Vasodilation When you warm up after a cold plunge or shower, blood vessels expand (vasodilation), Carpenter says. When that happens, the oxygen- and nutrient-rich blood gets pumped back to your tissues.
Inflammation Reduction Pain and swelling often stem from inflammation.
By reducing pro-inflammatory chemicals in the body, cold water therapy may help calm the body's response to injury or strain, Carpenter says.
“It's much like applying ice to a sprained ankle.”
Nervous System Stimulation Entering frigid water prompts the brain to release endorphins — the same happy chemicals you get from a good workout. It also activates the sympathetic nervous system (SNS), stimulating a rise in noradrenaline (a hormone involved in the fight-or-flight response) and dopamine (the “happy hormone”) and a decrease in cortisol (the “stress hormone”).
“This can elevate your mood,” says Joseph Hribick, DPT, clinical assistant professor of physical therapy at Lebanon Valley College in Annville, Pennsylvania.

Options for cold water therapy include:

Cold Water Immersion Like the name suggests, cold water immersion involves lowering yourself in cold water up to your neck or submerging a specific area of the body, like an arm or a leg. You can do this in a tub, basin, or natural body of water. There's no universal, official guidance for the optimal temperature or time limit, but most people use water that's at or below 59 degrees F and remain submerged for 10 minutes at most.
Contrast Water Therapy This method is similar to cold water immersion, except that it alternates exposure to cold water with exposure to hot water. There's no standard protocol, but most studies involve using temperatures between 50 to 59 degrees F (cold) and 100 to 104 degrees F (hot) for 1 to 2 minutes at a time.
Cold Showers Taking a frigid shower offers a way to ease into cold water therapy, though it may not be as beneficial as cold water immersion, says Scott J. Biehl, DO, an orthopedics and sports medicine physician at Rochester Regional Health in New York.
As with immersion, it's best to gradually turn down the temp, and stay in for 10 minutes at most.
Wim Hof Method The Wim Hof Method, invented by Dutch extreme athlete Wim Hof, combines cold water therapy, breath work, and commitment. By commitment, Hof means dedication to the practice and exercising self-control and willpower.

Some research suggests that a cold plunge or shower could benefit your mind and body in the following ways:

1. May Aid Muscle Recovery

There's a good reason cold water immersion is particularly popular among athletes. The practice may help delayed onset muscle soreness (DOMS) and speed up muscle recovery, says Sabrena Jo, PhD, senior director of science and research at the American Council on Exercise in Lawrence, Kansas.

A 2023 review backs this up. The report included 20 studies where healthy adults either submerged themselves in water with temperatures from 41 to 59 degrees F or practiced passive recovery methods, such as rest, after exercise. The researchers found that those who took a chilly dip had significantly less DOMS in the 24 hours post-workout compared with the control group.

A 2022 systematic review and meta-analysis of 52 studies found similar results, suggesting cold water immersion significantly reduced soreness and fatigue and improved perceived recovery in the 24 hours after high-intensity exercise.

That said, Dr. Jo cautions not to use cold water immersion after strength training if your goal is to build muscle. “It may blunt hypertrophy [muscle growth] if you use it regularly post-resistance training,” Jo says.

2. May Help Relieve Pain

Cold water therapy is often used in physical therapy settings to lower inflammation and acute pain.

“Cold therapy is a gold standard for pain management because it can be so effective for acute injuries, such as a sprain, or for post-operative swelling, as the cold can slow down nerve signals and reduce inflammation,” says Vanessa Walker, DPT, Los Angeles–based founder and clinical director of Walker Wellness and Body Work and board member of Find Massage Therapist.

Some research suggests it could also help with certain chronic pain conditions, such as gout, a form of inflammatory arthritis. For example, a 2022 study of 76 people with gout found that those who participated in two weeks of cold immersion therapy experienced a significant reduction in pain compared to the control group.
They also had notable improvements in their mood, joint mobility, and quality of life.

Contrast water therapy may be a helpful pain management tool as well, according to one report, which reviewed eight studies and suggests that it is more effective in treating knee osteoarthritis pain than heat therapy alone.

However, cold water therapy isn't currently recommended as a long-term solution for chronic pain conditions, says Noah Raizman, MD, a physician at The Centers for Advanced Orthopaedics in Washington, D.C.

“Its role in chronic pain management is not well supported by current research and it's rarely recommended as a long-term solution,” Dr. Raizman says. “Overall, it's best applied to short-term pain and post-workout fatigue rather than ongoing or chronic conditions.”

3. May Boost Your Mood

A cold water plunge may temporarily make you feel invigorated, and possibly even elated, due to its impact on the nervous system.

Additionally, some small studies suggest cold water immersion could be an effective complementary treatment for depression and anxiety. For example, a 2022 study of 53 participants found that those who participated in an eight-session sea swimming course reported a significant reduction in depression and anxiety by the end of the course.
After three months, their severity scores had slightly increased but remained lower than at the course's beginning.

However, other research suggests cold water immersion's mood-boost effects only last about 12 hours.

A 2025 systematic review found little evidence to support the claim that cold water therapy has a lasting impact on mood or immunity.

Cold water therapy is generally safe but could be risky if you are in the water too long or you have certain medical conditions, says Irvin Sulapas, MD, a sports medicine physician at UTHealth Houston.

“Cold water does put stress on the body, so if someone has a heart condition, high blood pressure, or other circulatory issues, they should consult their primary care physician to see if it's okay,” Dr. Sulapas says. Those with diabetes or Raynaud's syndrome should also speak with their healthcare team first.

Even if you don't have an underlying health condition, submerging your body in cold water also increases your risk of hypothermia, a potentially life-threatening condition that develops when your body temperature drops too low.

Hypothermia can occur much more quickly in water because water is more effective than air at drawing heat from the body.

What's more, hypothermia can happen anytime the water temperature dips below 70 degrees F.
It's important to get out of the water immediately if hypothermia symptoms (such as confusion or fatigue) occur.

Additionally, plunging into frigid water may cause you to involuntarily gasp and hyperventilate, which can raise the risk of drowning.
Entering the water gradually, allowing your body to acclimate, can help prevent hyperventilation.

Finally, although the temperatures aren't typically frigid enough to cause frostbite, you may experience skin redness and irritation, says Dr. Biehl.

If you plan to practice cold water immersion in an open body of water, be sure to take a partner with you — even if you're a strong, experienced swimmer — in case of emergency.

If you need to recover quickly after a bout of intense cardio or endurance training, cold water therapy may help you bounce back, Sulapas says.
“After resistance training, it could hinder strength gains, so it's only advised to do cold water immersion therapy after aerobic exercise,” he says.
You might also want to try cold water therapy to boost your mood, Carpenter adds.

“Like many health-related activities, this can be hugely beneficial, but it's not for everyone, and even a person who responds positively to it may not experience those benefits all of the time,” says Jessica McManus, PT, owner of Full Circle Wellness in Newbury, Massachusetts.

Like people with circulatory problems, those with disorders such as diabetic neuropathy (a type of nerve damage) should check with their doctor before trying cold water therapy, Sulapas says.

“It could put their nerves into a state of numbness where they don't know when the water is too cold for them and can cause damage to their soft tissues, like frostbite,” Sulapas says.

Cold therapy may also exacerbate certain chronic pain conditions, says John Gallucci, Jr, DPT, CEO of JAG Physical Therapy based in West Orange, New Jersey. If you have a disorder such as complex regional pain syndrome (CRPS), he suggests talking with your healthcare team before trying it.

If you're new to cold water therapy, hopping into a frigid lake or a tub filled with ice may be too much of a shock, so consider starting with cold showers.

“We recommend our athletes and patients start with a cold shower or an outdoor pool that's around 65 degrees F,” Gallucci says. At first, each session may be as short as 10 to 30 seconds. You can slowly increase the time over days (or weeks) as you build up tolerance. “Gradual acclimation is key to safely adapting to colder temperatures,” Gallucci says.

Once you're ready for a cold bath, simply fill your tub with the coldest water you can get from your tap. This will most likely fill your tub within the range of 50 to 60 degrees F, Biehl says. Double-check by dipping a thermometer in the water. If your water isn't cold enough to reach 60 degrees, that's okay; you can add ice after your tolerance to cold exposure has increased.

If you prefer to plunge into a natural body of water, look online for information about options in your area. (The Centers for Disease Control and Prevention provides water quality information by state, so you can avoid bodies of water that pose health and safety risks.)

In addition, the National Weather Service offers daily water temperature data. Look for water between 50 and 60 degrees F and bring a buddy for support. Don't try it alone.

Once you're ready for a dip, step carefully into the water and slowly lower yourself until you're submerged from the neck down. You can also target a specific region of the body. For example, only sit in water high enough to cover the legs to boost recovery following an intense lower-body strength routine or cycling session, Biehl says. “Try to sit for 2 or 5 minutes and work your way up to 10 minutes.”

Get out once you start to shake or shiver, recommends Jonathan Leary, DC, a chiropractor and CEO and founder of Remedy Place, a wellness facility in New York City and California that offers ice bath classes. “That's your body telling you that you've reached your max time for the day,” he says.

Your experience with cold water therapy will vary depending on the type you choose and your intended wellness goals. Expect to submerge your body (or parts of your body) in water at least 59 degrees F. As you advance, you can incrementally reduce the temperature to as low as 40 degrees F, if you wish.

Before

If you're doing cold water therapy at home, you may choose to go without clothes. In public places, you can wear a swimsuit or shorts and a light top or sports bra. Before stepping in, gather essentials like a towel and dry clothes for afterward. “It's also important to mentally prepare by engaging in deep breathing or mindfulness to help manage the initial shock of the cold,” Gallucci says.

During

Entering cold water may take your breath away at first, “and you can feel your heart race,” Biehl says. Gallucci recommends staying calm and focusing on slow, controlled breathing to overcome the initial shock.

In the beginning, you might spend only a few minutes in the cold water. You'll have to gauge how your body responds and tailor your practice accordingly. “There's a very fine line between what each person can tolerate,” says Matthew Welch, CSCS, an exercise physiologist at the Hospital for Special Surgery in New York City. Just because your friend can sit for five minutes doesn't mean you can.

“Numbness, dizziness, or uncontrollable shivering are signs that it's time to exit,” Gallucci says. “For those using localized cold therapy (such as for an ankle or knee), the same principles apply on a smaller scale.”

After

Once you get out of the water, drying off and changing into warm, dry clothes is essential, Gallucci says. “Many people follow up with light movement, a warm drink, or contrast therapy (alternating hot and cold) to help stabilize circulation and promote recovery,” he says. You may feel an initial energy boost or endorphin rush, followed by a period of relaxation, Gallucci continues. Take note of your body's response and adjust your next session accordingly, Gallucci suggests. Once you're warmed up, you may notice that you have greater mobility and less pain. But if you experience adverse effects, it may signal that you did more than your body can handle.