If you’ve seen people take ice baths or cold showers and wondered if they’re onto something or just plain crazy, you’re not alone. Cold-water immersion (CWI) – exposing the body to icy water on purpose – has exploded in popularity recently. From pro athletes dunking in ice tubs after games to wellness influencers and biohackers touting morning cold showers, many are “taking the plunge” in hopes of boosting their health and well-being.[1]
So, what exactly is cold-water immersion? In simple terms, cold-water immersion may involve any activity where you submerge yourself (partially or fully) in cold water, usually icy or near-icy temperatures, for a short time. This could mean hopping into a tub filled with ice water, jumping into a chilly lake, or just turning your shower cold for 30 seconds. People are drawn to it for various purported benefits – reduced inflammation, faster workout recovery, a jolt of alertness, improved mood, and even claims of enhanced metabolism and longevity. But is subjecting yourself to shivers good for you? Let’s explore the science-backed benefits, the possible risks, and how to practice cold-water immersion safely.
Benefits of Cold-Water Immersion
Enthusiasts of cold-water immersion aren’t just bragging about their tolerance for torture – many genuinely swear by how it makes them feel and the changes they’ve seen. Science is starting to back up some of these benefits, although research is ongoing. Here’s a look at some key potential benefits:
Physical Benefits: Reduced Inflammation and Faster Recovery
One of the most touted benefits of cold water immersion is its effect on physical recovery. Athletes have used ice baths for decades to combat delayed-onset muscle soreness after intense exercise. The cold causes blood vessels to constrict, which can reduce swelling and tissue inflammation, highlighting the health benefits of cold water immersion. Research indicates that icy water can reduce exercise-induced muscle damage and soreness, helping muscles recover faster.
Less damage and inflammation means less pain and stiffness so you can perform again sooner. A review of studies confirmed that post-exercise cold water therapy significantly decreases delayed-onset muscle soreness (DOMS) and markers of muscle damage, allowing athletes to get back to training faster.
Beyond workouts, dialing down inflammation might have broader health perks. Some proponents suggest it could bolster immunity or overall well-being. One large study found that people who took daily cold showers called in sick 29% less often than those who didn’t, hinting that regular cold exposure might increase resilience to common illnesses.
Mental Benefits: Increased Alertness and Improved Mood
Ask anyone who’s tried a cold shower in the morning – the immediate zing of cold is like a jolt of electricity to your brain. Cold-water immersion triggers a “fight or flight” response in the body, leading to a rush of adrenaline and other stress hormones that can make you feel alert and energized. For instance, one study found that immersion in cold water (~14°C) caused a massive spike in norepinephrine (a hormone related to focus and alertness) by 530%, along with a 250% increase in dopamine. No wonder many people feel wide awake and even euphoric after a cold dip![2]
Beyond the initial adrenaline high, many people also report mental benefits. They feel that enduring the frigid water builds mental toughness. If you can handle an ice bath, other stressors may feel more manageable, showcasing the effect of cold water on resilience. Indeed, some science backs up mood boosts, too. In a recent experiment, participants who underwent a short whole-body cold bath reported feeling more active, alert, and inspired and less distressed and nervous afterward. In other words, cold water seemed to lift their mood and reduce anxiety levels. Some preliminary evidence suggests that repeated cold exposure can lower stress hormone levels over time, indicating the body becomes more resilient to stress.
Metabolic Benefits: Boost Metabolism & Brown Fat Cell Activation
Cold-water immersion can also give your metabolism a bit of a boost. When exposed to cold, your body has to work harder to maintain its core temperature. This means burning more calories to produce heat. Research has shown that being immersed in cold water can increase metabolic rate substantially during the exposure – one study noted a 350% rise in metabolism during a 14°C immersion as the body revved up to keep warm. So, a shivery soak might burn a few extra calories (though it’s not a weight-loss miracle on its own).
More intriguingly, repeated cold exposure might change your body fat composition. Adults have small amounts of brown adipose tissue (brown fat), a special type of fat that burns energy to produce heat. Cold exposure is one trigger that can activate brown fat. Over time, routinely exposing yourself to cold can increase your brown fat stores. A clinical study by the National Institutes of Health found that after a month of sleeping in a 66°F (19°C) room, young men saw a 42% increase in brown fat volume, a 10% boost in activity, and improved insulin sensitivity. Their bodies adapted to the calm environment by developing more “fat-burning” tissue, making them better at handling blood sugar – a positive sign for metabolic health.
These metabolic changes have big-picture implications: more brown fat and better insulin sensitivity could lower the risk of metabolic disorders like obesity and diabetes. Some biohackers and longevity enthusiasts believe regularly stressing the body with a cold can activate cellular pathways that slow aging and promote longevity. This idea comes from hormesis, a minor stress triggering a beneficial adaptive response. Interestingly, animal studies support this notion – for example, one experiment showed that fruit flies subjected to mild cold stress lived longer and aged more slowly than those kept at normal temperatures. Of course, humans aren’t fruit flies, but it hints that cold-induced hormesis might have anti-aging effects, suggesting potential health benefits from cold exposure.
Risks and Considerations of Immersion in Cold Water
As invigorating as cold-water immersion can be, it’s not all upside; the nervous system can react unpredictably to extreme conditions. Dunking yourself in freezing water does carry some risks, 
especially if done incorrectly or if you have underlying health issues.
Cold Shock and Hypothermia: The first risk to know is the cold shock response, which is crucial when considering cold therapy. Plunging into frigid water triggers a sudden heart rate and blood pressure spike and can cause an involuntary gasp. If your head is underwater when that gasp happens, you could inhale water and drown within seconds. The shock response to cold also places stress on your heart. For people with heart conditions or uncontrolled high blood pressure, this can be extremely dangerous – experts strongly advise those individuals to skip extreme cold-water exposure or at least get medical clearance first.
Even healthy people can sometimes experience a dramatic cold shock, which can sometimes trigger abnormal heart rhythms. Safety organizations warn that water below 60°F (15°C) can be lethal to an unacclimated person in under a minute. Your body loses heat much faster in water than in air—up to 25 times faster—so hypothermia is a real concern if you stay in too long. Extreme cold can also cause frostbite on exposed extremities.[3]
Other Considerations: The health benefits of cold-water immersion can vary significantly based on individual circumstances. Besides the big safety risks, there are a few things to remember. First, it’s uncomfortable – intense cold can cause pain, panicked breathing, or confusion. This is why gradual exposure and proper techniques (like breathing control) are essential. Additionally, if you’re an athlete focused on building muscle or strength, be aware that jumping into an ice bath right after every lifting session might slightly blunt your gains. Taming inflammation too quickly could reduce the signaling for muscle adaptation. Some studies found that regular post-workout ice baths hindered muscle growth and strength gains over time, indicating the complex effects of cold water. Lastly, remember that individual tolerance varies. Not everyone will feel great after a cold dunk, and that’s okay – what works as a wellness practice for one person might not suit another, as the benefits of cold vary by individual.
Ice Baths vs. Cold Showers
Ice baths and cold showers are two popular methods of cold water therapy that offer distinct benefits and challenges for individuals seeking improved recovery, enhanced circulation, and increased mental resilience. Both techniques harness the natural advantages of cold exposure but differ in application, intensity, and overall experience. An ice bath typically involves submerging the body in a tub filled with near-freezing water augmented with ice, rapidly reducing muscle and skin temperatures. This sudden cooling effect can help decrease inflammation, relieve muscle soreness, and trigger the release of endorphins, making it a favored choice among athletes after intense workouts. However, the extreme nature of ice baths may lead to significant discomfort and requires careful timing and monitoring to avoid adverse reactions.
In contrast, cold showers offer a more gradual introduction to cold water therapy, as the body is exposed to a continuous stream of cool water that slowly lowers its temperature and stimulates circulation. This method is more accessible for daily use, providing a convenient way to boost alertness, enhance mood, and support immune function without the shock of complete immersion. Moreover, cold showers allow individuals to adjust the water temperature incrementally according to personal tolerance, ensuring a gentler transition that minimizes potential risks. Ultimately, deciding between an ice bath and a cold shower depends on individual goals, physical condition, and lifestyle preferences, as both methods provide unique benefits of cold. Whether one opts for the rapid, intense recovery benefits of an ice bath or the steady, manageable effects of a cold shower, both practices contribute to improved performance and mental fortitude when practiced safely and consistently. In summary, while ice baths and cold showers effectively harness cold water therapy benefits, understanding their unique mechanisms and adjusting the approach based on personal recovery needs and lifestyle considerations ensures optimal results and well-being.
How to Cold Plunge Safely
If you’re intrigued by the potential mental health benefits of cold and want to try cold-water immersion, it’s important to do it safely and smartly. Here are some practical tips to get started safely:
- Start Gradually with taking a cold plunge: You don’t have to jump into a frozen lake on day one. Begin with something milder, like ending your regular warm shower with 15-30
seconds of cold water. Or try a cool (not ice-cold) bath. Gradually increase the cold intensity and duration as you get used to taking a cold plunge. Many beginners start at about 30 seconds to 1 minute of cold exposure and slowly work up to a few minutes over days or weeks. You’re training your body (and mind) to tolerate the cold, so patience is key. - Talk to Your Doctor (if needed): If you have any medical concerns – especially heart or blood pressure issues – check with a healthcare provider before you start. Getting the green light is better than putting yourself at risk.
- Set Safe Conditions: Ensure your environment is safe and controlled. If you’re using a bathtub or plunge tank at home, ensure you have a non-slip surface and can get out quickly (just in case the cold makes you lightheaded). If you’re doing an outdoor plunge, never avoid dangerous waters alone. Stay away from rivers or ocean spots with strong currents in cold weather – the last thing you want is to be swept away or trapped under ice. Have a buddy or someone as a spotter, especially for open water swims.
- Mind the Temperature and Time: Know the water temperature you’re getting into. Extremely cold water (below ~50°F or 10°C) will shock you hard, so don’t underestimate it. Water around 59-68°F (15-20°C) is a gentler entry point for beginners. Use a thermometer if you’re prepping an ice bath, and don’t stay in too long. A few minutes is plenty for most benefits. Even experienced cold plungers usually cap it at 5-10 minutes in ice water. When you feel numb, or your shivering intensifies, it’s time to get out and warm up.
- Control Your Breathing During Cold Therapy: That first blast of cold will make you want to gasp and pant. Instead, try to take control of your breathing as quickly as possible. Take slow, deep breaths – this helps calm your body’s initial panic response. Some people focus on counting breaths or using a meditative breathing pattern. Keeping your breathing steady will help you resist the urge to jump right out and allow your body to settle into the cold more comfortably.
- Warm Up Afterwards: Have a plan to warm up immediately after your cold dip. Keep towels and warm clothing handy (if you’re outside, prep a warm jacket, hat, and so on). Once you’re out of the cold, move around to get your blood flowing again and maybe sip a warm drink. Warm up gradually – don’t sprint into a scorching hot shower immediately, as a rapid temperature swing isn’t ideal. Your body should return to normal temperature over 10-30 minutes after exposure to cold water. Enjoy the refreshed feeling and respect your body’s need to recover from the cold stress and potential delayed onset muscle soreness.
seconds of cold water. Or try a cool (not ice-cold) bath. Gradually increase the cold intensity and duration as you get used to taking a cold plunge. Many beginners start at about 30 seconds to 1 minute of cold exposure and slowly work up to a few minutes over days or weeks. You’re By following these steps, you can reap the rewards of cold-water immersion while minimizing the risks. Always listen to your body – shivering is okay, but uncontrollable shivering, numbness, or dizziness are signs you’ve had enough, emphasizing the importance of safe exposure to cold.[4]
Cold-water immersion is a thrilling experience for the body – a short, sharp shock that, when done right, can yield surprisingly positive effects. It may help reduce inflammation, speed up muscle recovery, boost mood and alertness, rev up metabolism, and even engage cellular pathways linked to longevity. On the flip side, we also know it comes with serious risks if misused, from cold shock and hypothermia to undue strain on the heart.
So, is it good for your health?
The answer is yes—for many people, it can be, as long as it’s approached sensibly. When practiced safely, cold-water immersion can be an invigorating ritual that nudges your body toward 
beneficial adaptations. However, it’s not for everyone and is definitely not a magic cure-all.
Who might benefit most? Generally, healthy individuals looking for a naturally boost stem cells or a recovery aid:
- Athletes and fitness buffs who want to reduce muscle soreness and bounce back faster after hard workouts.
- Busy professionals or students seeking a quick, caffeine-free jolt of energy and alertness – for example, a bracing cold shower to start the day.
- Wellness enthusiasts and biohackers who enjoy challenging their bodies and exploring hormetic stress practices.
- Those looking to improve mood or resilience – if you struggle with grogginess or stress, taking a cold plunge can be a potent mood lifter and confidence builder.
On the other hand, who should be cautious or avoid it? Anyone with significant cardiovascular issues (heart disease, history of heart attacks, uncontrolled high blood pressure),COPD, kidney failure or liver disease should probably skip the DIY ice baths unless cleared by a doctor. Also, if you hate the cold or get no joy from the post-plunge high, there’s no need to force it.[5]
Cold-water immersion is a powerful general wellness tool that, when used wisely, can invigorate you. But, like any tool, you must respect its risks, as the effects of cold water can vary greatly among individuals. If you take the plunge, ease in safely, listen to your body, and enjoy the invigorating ride. Happy plunging!
Published Clinical Citations
[1] ^ Mawhinney C, Heinonen I, Low DA, Han C, Jones H, Kalliokoski KK, Kirjavainen A, Kemppainen J, Di Salvo V, Weston M, Cable T, Gregson W. Changes in quadriceps femoris muscle perfusion following different degrees of cold-water immersion. J Appl Physiol (1985). 2020 May 1;128(5):1392-1401. doi: 10.1152/japplphysiol.00833.2019. Epub 2020 Apr 30. PMID: 32352343.
[2] ^ Ajjimaporn A, Chaunchaiyakul R, Pitsamai S, Widjaja W. Effect of Cold Shower on Recovery From High-Intensity Cycling in the Heat. J Strength Cond Res. 2019 Aug;33(8):2233-2240. doi: 10.1519/JSC.0000000000003017. PMID: 31343603.
[3] ^ Knill-Jones J, Shadwell G, Hurst HT, Mawhinney C, Sinclair JK, Allan R. Influence of acute and chronic therapeutic cooling on cognitive performance and well-being. Physiol Behav. 2025 Feb 1;289:114728. doi: 10.1016/j.physbeh.2024.114728. Epub 2024 Nov 6. PMID: 39515683.
[4] ^ Moore E, Fuller JT, Bellenger CR, Saunders S, Halson SL, Broatch JR, Buckley JD. Effects of Cold-Water Immersion Compared with Other Recovery Modalities on Athletic Performance Following Acute Strenuous Exercise in Physically Active Participants: A Systematic Review, Meta-Analysis, and Meta-Regression. Sports Med. 2023 Mar;53(3):687-705. doi: 10.1007/s40279-022-01800-1. Epub 2022 Dec 17. PMID: 36527593.
[5] ^Allan R, Mawhinney C. Is the ice bath finally melting? Cold water immersion is no greater than active recovery upon local and systemic inflammatory cellular stress in humans. J Physiol. 2017 Mar 15;595(6):1857-1858. doi: 10.1113/JP273796. Epub 2017 Jan 24. PMID: 27991663; PMCID: PMC5350472.