Cold plunges may have benefits like a stronger immune system and improved cardiovascular health, but more research is needed to know for sure. They also come with safety risks, especially for those with heart problems.

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A cold plunge, also known as cold water immersion, involves submerging yourself in cold water at about 50°F (10°C) or less for 30 seconds to a few minutes. It may involve anything from diving into an icy lake or simply hopping in a tub of cold water.

If you get goosebumps just thinking about it, you’re not alone. Research suggests that cold therapy may have many benefits — but there are also potential risks. Before you take the polar plunge, here’s what to know.

In recent years, you’ve likely heard someone talk about the benefits of cold-water therapy (cryotherapy) — whether it’s an ice bath, a cold shower, or a cold plunge. The practice isn’t anything new — it dates back to ancient Greece, with Hippocrates saying that it can help retain strength and vitality.

So far, research on the benefits of cold plunges looks promising, but more is needed before drawing any definite conclusions.

But at this point, here’s the breakdown of some of the potential benefits that the science shows:

  • Improved heart health: In a 2016 review, researchers noted several studies that suggest cold plunging or cold water therapy can boost blood flow, reduce heart rate, and improve overall cardiovascular health.
  • Improved metabolism: The same 2016 review suggests that cold plunges may have beneficial effects on metabolism and body fat, including a reduced risk of metabolic diseases and reduced body fat.
  • Reduced pain: There’s a reason ice baths have been recommended for sore muscles for generations — according to a 2022 review, numerous studies have shown that cold water therapy can reduce swelling, lessen the perception of pain in the body, and speed muscle recovery.
  • Boosted mood: There’s a wealth of research to suggest that a cold plunge results in a temporary mood boost that may extend to long-term mental health benefits, including reduced anxiety and depression.
  • Improved insulin sensitivity: According to a 2022 review, numerous studies have shown that voluntary cold water exposure can improve insulin sensitivity and reduce insulin resistance.
  • Stronger immune system: In a 2016 study on cold showering — which has been shown to have a similar impact to cold plunging — researchers found the practice may improve the immune system of otherwise healthy adults. Showering in cold water, or for at least 30 seconds, resulted in a 29% reduction in sick days in participants. By comparison, regular physical activity resulted in a 35% reduction in sick leave.
  • Reduced inflammation: Cold plunges have been heavily associated with reduced inflammation. Since heightened inflammation is associated with a number of chronic conditions, this could potentially help stave off disease.

Even though cold plunges are strongly associated with numerous health benefits, researchers point out that most of the research has a high risk of bias. For instance, many of the sample sizes are small, and the placebo effect cannot be ruled out.

Furthermore, scientists note that many people who opt to cold plunge are also people who are more likely to make other healthy lifestyle choices, like regular exercise and eating well.

There are potential dangers to a cold plunge, including:

  • Cardiovascular stress: Sudden cold-water exposure can cause your blood pressure and heart rate to spike, which can be particularly problematic for those with heart conditions. If you have a heart condition, talk with your doctor before taking a plunge, or consider skipping the practice altogether.
  • Hypothermia: Extended cold-water exposure can cause hypothermia, which can be life threatening in severe cases. For that reason, it’s best to keep plunges short — within a few minutes.
  • Hyperventilation: The cold water can cause your airways to tighten, making breathing difficult. If you have a respiratory condition like asthma, always talk with your doctor before attempting a cold plunge.
  • Muscle cramps or shock: The shock of the cold water may cause disorientation, muscle cramps, or issues controlling movement. For that reason, it’s best to start with warmer temperatures before working your way to very cold ones.
  • Drowning: Due to the above issues, drowning is a potential possibility.

Due to potential risks, talk with your doctor if you have any preexisting conditions before trying the plunge. Listen to your body, and don’t endure more than you can handle for the sake of possible health benefits.

Wim Hof and cold plunges

A 2024 review also found that the Wim Hof method, a type of cold water immersion and breathwork technique, lacks substantial evidence and needs further review.

As of 2023, there have been 21 deaths and 18 injuries reported from practicing the Wim Hof method due to a loss of consciousness and hyperventilation in freezing, cold water. As of publication, a lawsuit has been brought forward because of these deaths.

How long should you stay in a cold plunge?

It’s a good idea to start with just 30 seconds in cold water. From there, you can observe how your body reacts and gradually work your way up to a few to several minutes.

It’s worth noting that in a 2016 review, researchers found no difference between 30, 60, or 90 seconds of cold showering — the benefits appeared to plateau after about 30 seconds.

If you have a heart condition or are in very cold water, it may be best to limit your time to under 2 minutes.

Should you dunk your head in a cold plunge?

You can dunk your head in a cold plunge if you desire — which may extend benefits from head to toe. So far, however, there’s no research to suggest if submerging your head is beneficial.

If you’re prone to ear infections, you may want to avoid fully submerging your ears. You can also check out this article to learn easy ways of getting water out of your ears.

Is it OK to cold plunge every day?

So far, there’s no evidence that cold plunging daily is harmful unless it’s already not advised for you. If you find it to be a quick and caffeine-free way to wake up in the morning, it may even provide benefits.

Cold plunges may offer potential benefits like improved heart health, reduced inflammation, and an improved mood, but more research is needed to know for sure.

There are potential safety risks with cold plunging, including cardiovascular stress or drowning, especially for those with heart or respiratory conditions. Those with breathing conditions like asthma may also be at higher risk for dangerous side effects.

If you have a preexisting health condition, always speak with your doctor before taking the plunge.