Written by Natalie Grigson, Writer
The idea of submerging the body into cold water for health benefits is nothing new. In fact, cold water therapy has been used for centuries1 to treat everything from sports injuries to malaise. It seems that these days, though, cold water therapy – and cold plunges in particular – have become something of a wellness trend.
While we’ve all probably heard the anecdotes about how cold plunges impact people’s health, today we’ll be looking at the science behind these claims. We’ll answer the questions: What is a cold plunge? What are the risks and benefits? How should you use a cold plunge to the greatest effect?
Remember, before you jump into a cold plunge, you should be sure you are healthy and don’t have any of the risk factors we’ll discuss below. If you’re unsure, speak to your doctor before taking the plunge.
What is a Cold Plunge?
Technically, you can “cold plunge” in any body of water that is below 60 degrees Fahrenheit2 by submerging everything but your head and neck. However, increasingly popular are cold plunge pools or tubs, which are tubs that are designed specifically to chill the water.
They do this with a chiller or refrigerator unit3, and the benefit of this is that you can set the tub to whatever temperature works best for you. Also, the water in these tubs is filtered and continuously circulating, so the water may be cleaner than in a natural body of water or an ice bath.3
What are the Benefits of a Cold Plunge?
Even though cold water therapy has been around for centuries, there are still relatively few studies on its benefits. That said, one of the benefits that has been the most studied and confirmed by science is improving muscle soreness and reducing inflammation4. This is why you’ll often see athletes soaking in an ice bath post-game.
Other benefits of cold water therapy may include:
- An immune system boost: A 2016 study5 looked at the effects of cold showers. Participants who switched to taking cold showers for 30 to 90 seconds for 90 days called in sick to work less frequently than those who did not. Even though this study was done on cold showers specifically, it is possible that cold plunges could provide the same benefits to the immune system.
- Reduced depression and anxiety: Research shows6 that exposure to cold water can decrease levels of depression and anxiety. Dr. Tracy Zaslow, a sports medicine physician at the Cedars-Sinai Kerlan-Jobe Institute says, “Nobody knows exactly why it even helps you”.4 She adds that it could be changes in adrenaline, cortisol, or dopamine, but that the data doesn’t show exactly why cold water can boost mood in this way.4
- Improved circulation: According to UCLA Health, cold water forces the body to increase blood flow, and this is likely why cold water can decrease muscle recovery time after exercise.2
- An increased metabolism: The body expends more energy when it is cold.2 However, if you’re expecting cold plunges to magically help you shed pounds, it isn’t so simple. Research is limited on the subject, and one study that was done in 20147 showed that while cold exposure can increase metabolism and burn calories, it also increases appetite. As such, any weight that could have been lost in the experiment was made up for by extra food eaten.7
- Pain relief: Because cold therapy reduces inflammation in the body, it also reduces pain levels.2 Additionally, according to UCLA Health, the cold can interfere with your brain’s perception of pain, decreasing how quickly the sensation of pain travels through your nerves.2
Explore our top picks for the Best Cold Plunge Tubs.
Cold Plunge Risks
It’s important to understand that cold plunges are not without risks. In fact, the colder the water is and the longer you stay in it, the more dangerous it can be8.
The National Center for Cold Water Safety9 warns that immersing your entire body in water below 60 degrees Fahrenheit could kill you in less than a minute. This seems to be particularly true when it comes to bodies of water that require swimming to get out of, but there is still a risk with cold plunges.
To understand this, let’s take a look at what happens to the body when it enters cold water:
- Plunging into the cold water causes an immediate and rapid increase in breathing, heart rate, and blood pressure, which is known as “cold shock response.”8
- This places stress on the heart, making it pump harder.8
- Within a few minutes, blood rushes away from the extremities to the body’s core to protect vital organs.8
- This temporarily leaves the arms and legs without good blood flow, making them weaker.8
The side effects of this reaction in the body are not yet fully understood, but this immediate jump in both blood pressure and heart rate can increase the risk of heart attack and stroke.4 After the body calms from the initial cold shock, there is an increased risk of hypothermia10 and frostbite.4
This is why it is so important to start cold plunges very gradually, as some evidence shows that the dangers may be mitigated if you become used to cold water therapy over time.10
That said, there are certain people who should never do cold plunges.
Who Should Not Do a Cold Plunge?
Because cold plunges increase heart rate and blood pressure, as well as impact the circulatory system, certain people should avoid cold plunges entirely. This includes:
- People with heart disease10
- Anyone with any sort of cardiac history8
- Those with Raynaud’s syndrome10
- People with high blood pressure10
- People with low blood pressure8
- Those with any sort of peripheral vascular disease10
- People with diabetes and vascular issues10
- People taking Beta blockers8
- People with a low resting heart rate8
Even if you are healthy and meet none of the criteria on the list above, you’re encouraged to always cold plunge with somebody else present11 in case of an emergency. We also recommend that everyone check with their doctor prior to doing a cold plunge, particularly if you are pregnant or have other health concerns outside of the aforementioned list.
How to Do a Cold Plunge
First, you start by easing into cold plunging.11 To help avoid risks, you can start by taking cold showers to prepare your body for the shock of getting into a cold plunge. Once you have gotten used to this, start out slow, with experts recommending no more than five minutes for your first several plunges.11
Since buying your own cold plunge can be expensive, we’d recommend trying it out somewhere before making this investment. For example, various gyms, spas, physical therapy centers, and wellness centers have cold plunges now. There are also specific businesses that specialize in cold plunge and cryotherapy.
Best Cold Plunge Temperature
Research shows that the best cold plunge temperature is somewhere between 51 and 59 degrees Fahrenheit12. To put this into perspective for you, the average swimming pool is somewhere between 78 to 82 degrees13, so the cold plunge will feel shockingly cold.
Cold Plunge Costs
A true cold plunge will have a built-in cooling mechanism that filters the water, circulates it, and allows you to set the temperature as you please, as opposed to an ice bath, which is a tub that you’ll have to fill with water and ice.3 As such, cold plunge tubs can be expensive, but the costs seem to vary widely, ranging anywhere from 100 to 30,000 dollars. Depending on the size of your home and budget, you may prefer doing cold plunges at a local gym, spa, or business specializing in this service.
FAQs About Cold Plunges
Can you do cold plunges every day?
No, you should not do cold plunges every day. The reason for this is that your body needs time to recover14 in between cold plunges.
How long should you stay in a cold plunge?
When you’re first starting out with cold plunges, you should stay in the water for only one or two minutes.14 — and certainly no more than five.11 After you have gotten used to this, you can work your way up, but you should never stay in longer than 15 minutes as this could be dangerous.4
How often should you cold plunge?
It’s recommended that you do a cold plunge two or three times per week at most since your body needs time to recover in between sessions.14
Do cold plunges do anything to your brain?
There is some evidence that cold plunges can decrease depression and anxiety.6. However, the reasons why aren’t exactly clear.4 Cold plunges can also interfere with your brain’s perception of pain.2 This means that if frostbite were to set in, you may not be able to feel it due to the cold, so you should always limit your time spent in a cold plunge.
Can doing cold plunges help you lose weight?
There is some evidence that cold plunges can increase the body’s metabolism and ability to burn calories during the cold plunge, but the evidence is lacking that cold plunges can actually cause you to lose weight.7
Natalie Grigson
Writer
About Author
Natalie is a content writer for Sleep Advisor with a deep passion for all things health and a fascination with the mysterious activity that is sleep. Outside of writing about sleep, she is a bestselling author, improviser, and creative writing teacher based out of Austin.
Combination Sleeper
References:
- Allan, Robert., Malone, James., et al. “Cold for centuries: a brief history of cryotherapies to improve health, injury and post-exercise recovery”. National Library of Medicine. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9012715/. 2022.
- “6 cold shower benefits to consider”. UCLA Health. https://www.uclahealth.org/news/6-cold-shower-benefits-consider. 2024.
- Hounsell, Connor. “Ice Bath vs. Cold Plunge”. Comfort Home Recovery. https://comforthomerecovery.com/blogs/news/ice-bath-vs-cold-plunge. 2024.
- Fields, Lisa. “Taking the Plunge: Is Cold Exposure Worthwhile?”. Cedars-Sinai. https://www.cedars-sinai.org/blog/cold-exposure-therapy.html. 2022.
- Buijze, Geert A., Sierevelt, Inger N., et al. “The Effect of Cold Showering on Health and Work: A Randomized Controlled Trial”. National Library of Medicine. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5025014/. 2016.
- Mooventhan, A., Nivethitha. L. “Scientific Evidence-Based Effects of Hydrotherapy on Various Systems of the Body”. National Library of Medicine. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4049052/. 2014.
- Ravussin, Yann., Xiao, Cuiying., et al. “Effect of Intermittent Cold Exposure on Brown Fat Activation, Obesity, and Energy Homeostasis in Mice”. National Library of Medicine. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3895006/. 2014.
- Williamson, Laura. “You’re not a polar bear: The plunge into cold water comes with risks”. American Heart Association. https://www.heart.org/en/news/2022/12/09/youre-not-a-polar-bear-the-plunge-into-cold-water-comes-with-risks. 2022.
- “Why Cold Water is Dangerous”. National Center for Cold Water Safety. Webpage accessed October 4, 2024. https://www.coldwatersafety.org/the-danger.
- “Cold plunging: Do the benefits outweigh the risks?”. OSF Healthcare. https://newsroom.osfhealthcare.org/cold-plunging-do-the-benefits-outweigh-the-risks/. 2024.
- “Cold Plunging and the Impact on Your Health.” University of Utah Health. https://healthcare.utah.edu/healthfeed/2023/03/cold-plunging-and-impact-your-health. 2024.
- Machado, Aryane F., Ferreira, Paulo H., et al. “Can Water Temperature and Immersion Time Influence the Effect of Cold Water Immersion on Muscle Soreness? A Systematic Review and Meta-Analysis”. Springer Link. https://link.springer.com/article/10.1007/s40279-015-0431-7. 2016.
- “Managing Swimming Pool Temperature for Energy Efficiency”. U.S. Department of Energy. Webpage accessed October 4, 2024. https://www.energy.gov/energysaver/managing-swimming-pool-temperature-energy-efficiency.
- “Cold Plunge Therapy and Sauna: How Long and What Temperature?”. Denver Sports Recovery. Webpage accessed October 2, 2024. https://www.denversportsrecovery.com/blog/cold-plunge-therapy-and-sauna-how-long-and-what-temperature.