Cold Plunges: What the Science Actually Says
Your feed is full of people dunking themselves in ice water, claiming it'll transform your health. But what does the research really say?
Here's the truth: the evidence that cold plunges boost immunity and reduce stress is pretty thin. A 2025 systematic review published in PLOS ONE analyzed 11 studies and found the research is "constrained by few RCTs [randomized controlled trials], small sample sizes, and a lack of diversity in study populations." The review did find some time-dependent effects on inflammation and stress reduction, but concluded that high-quality research is still needed.
That said, cold water does trigger your body's rest-and-recovery response. Professional athletes use cold plunges to ease muscle soreness, reduce inflammation, and sharpen focus. These benefits have more consistent support in the science literature.
The Serious Risks
Cold shock is no joke. According to the American Heart Association, plunging into cold water triggers a rapid spike in heart rate and blood pressure. The National Center for Cold Water Safety warns that sudden immersion in water under 60 degrees Fahrenheit can kill a person in less than a minute. Remember, water pulls heat from your body 25 times faster than air.
This isn't hypothetical. In 2022, Kellie Poole, a 39-year-old mother of three from the UK, died during a cold-water therapy session in 51°F water. A coroner found that cold water triggered a fatal cardiac arrhythmia linked to an undiagnosed heart condition. The case prompted calls for regulation of cold-water therapy businesses.
Who Should Skip It
If you have heart problems, high blood pressure, or circulation issues, cold plunges aren't for you.
Still want to try? Talk to your doctor before trying one. PLEASE If you're healthy and want to experiment, keep it short (5 minutes max), stay above 60°F, and never do it alone.
And that $20,000 ice tub you saw on your feed? Save your money. A bathtub works fine.
Sources
Cain T, et al. Effects of cold-water immersion on health and wellbeing: A systematic review and meta-analysis. PLOS ONE, January 2025.
American Heart Association. You're not a polar bear: The plunge into cold water comes with risks. Dec 9, 2022.
BBC News. Kellie Poole: Woman's cold water therapy death concerns coroner. Sept 27, 2023.
New York Post. UK mom of three died of cardiac arrest during cold water therapy in river. Sept 27, 2023.
Harvard Health. Cold plunges: Healthy or harmful for your heart? Jun 1, 2025.
Mayo Clinic Health System. Can taking a cold plunge after your workout be beneficial? Jan 30, 2024.