A growing number of people embrace the health benefits of cold showers and icy baths, but not all claims of benefit have been proven.

There’s definitely enough positive evidence to make cold water therapy intriguing. But where are ice baths and cold showers valuable and what still isn’t known? And if you want to try it, how do you make sure you do it safely?

According to Healthline, “Cold water therapy is the practice of using water that’s around 59°F to treat health conditions or stimulate health benefits. ... The practice has been around for a couple of millennia. But recent adaptations include ice baths, brisk daily showers, outdoor swims, and cold water immersion therapy sessions.”

Cold water therapy is brief, lasting less than 15 minutes. Often, it’s not even that long.

The claims are broad, from boosting circulation to improving sleep quality and mood, decreasing inflammation and raising your energy level.

Proof is there for some claims but sparse for others.

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The known and unknown

A 2022 systematic review of dozens of studies that was published in Sports Medicine found that cold therapy reduced muscle soreness and aided strength recovery after high-intensity exercise. It also reduced creatine kinase in the blood, which comes from muscle damage from strenuous exercise.

Dr. Dominic King, a sports medicine physician in the Department of Orthopedic Surgery at the Cleveland Clinic, told Today Health there are other reasons people might want to take ice baths and cold showers. 

“It can numb pain receptors and bring down inflammation, so you can almost think of it as like a drug-free anesthetic,” King said. He noted that folks with rheumatoid arthritis, for instance, could get some relief from the swelling and discomfort they experience from the disease.

Healthline said the cold water reduces blood flow — and thus swelling and inflammation, which cause pain.

Health care providers have long used cold water immersion to lower body temperature in cases of dangerous heat stroke or high fever, as a review of existing studies in 2015 showed. 

HealthNews.com said ice baths could help burn fat by activating a pair of hormones, irisin and FGF21, that are found in metabolically-busy brown fat, which helps burn the more inert white belly fat. “These two ‘fat loss’ hormones are produced only when our muscles are shivering. Specifically, 10–15 minutes of shivering increases irisin to such a level that it has the same effect as an hour of moderate exercise. According to longevity expert and Harvard geneticist David Sinclair, brown fat burns energy to create heat and manage body temperature, which is why it’s activated by colder temperatures,” the article said.

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As Sarasota Magazine reported, “In 2021, the International Journal of Environmental Research and Public Health found that cold therapy had a positive effect on the cardiovascular system, specifically lipid profiles and blood pressure.

Claims that ice baths boost longevity are controversial at best. And many of the current claims — better sleep, focus and meditation — require more study to prove causation. King said, however, that he’s heard those and other claims of benefits from patients who use cold water therapy.

There’s discussion, too, of cold water therapy as a way of boosting one’s immune system. More study is needed there, too.

Wim Hof Method instructor Brock Cannon believes the practice offers important mental benefits. He told Sarasota Magazine that “cold exposure recharges your nervous system and brain, increasing adrenaline, serotonin and norephineprine, which help boost mood. He’s trained people who’ve seen a reduction in depression, anxiety and stress. He also teaches a concept called hormesis — that is, putting your body under short bouts of stress that can build mental resilience.”

The method is named for Dutch extreme athlete Wim Hof, an ardent advocate of cold water therapy. His method includes a specific breathing pattern, as well.

Not for everyone

Healthnews notes that some groups should avoid the practice, including people who have:

  • Circulation problems such as peripheral vascular disease.
  • Frostbite history.
  • Raynaud’s disease, which Raynauds.org describes as “a disorder of the small blood vessels of the extremities, reducing blood flow. When exposed to cold, the blood vessels go into spasms, which may cause pain, numbness, throbbing and tingling.”
  • An open wound or recent surgery.
  • Since cold water constricts the blood vessels, King said people with heart disease, high blood pressure, diabetes, venous stasis and cold agglutinin disease should avoid the practice, too.

Other sources suggest it’s not safe for those who are prone to seizures or fainting. Experts say to talk to your doctor before taking the plunge.

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Taking the plunge safely

Healthline, too, emphasizes checking first with your physician.

Healthline notes there’s no therapeutic reason to stay in cold water long.

King adds that 10 minutes is plenty and you should build up to that, also starting with warmer water and working your way to colder water.

When you get out, warm up, experts all agree, though don’t do it by jumping into a hot shower or bath. A sudden change in temperature can cause fainting.

If you’re not sure, you can side with Joel Snape, an opinion writer for The Guardian, who pondered the benefits and humorously rejected the notion of taking an ice-cold plunge: “If I’m going to be motivated to top up a wheelie bin with ice cubes and wince my way into it every morning, I need a bit less ‘statistically significant’ and a bit more ‘instant Captain America.’ I want to silence any disapproving neighbors with a porpoise-like somersault out of the frosty water, not feel a bit less sleepy in the late afternoon. There are loads of things I could already be doing to get faster, more proven benefits — sleeping more, drinking more water, not staring at my phone the instant I wake up — and I’m not doing any of them. If I want to improve my life, that is where I should start, not by disrupting the school run because I’ve gone full manatee.”