On a memorable trip to Oslo, Norway, a few years ago I was coaxed by the locals to participate in one of their favorite pastimes: plunging into the freezing waters of a fjord and then hastily retreating into the warmth of a nearby sauna. I tried to beg off the ice bath part; it seemed like almost everyone who jumped off the pier before me came up spluttering and gasping, swimming in panicked strokes back to the ladder. Some brave souls spent a few minutes trying to convince others that it wasn’t that bad as they tread in the dark, cold water, only to give up pretty quickly in the end.
The Norweigians in our group insisted that the cold plunge was an essential part of the sauna ritual. Among the seemingly magical properties being touted were soothed muscles, a focused mind and — potentially — a cured hangover.
The idea that immersing yourself in freezing cold water could have health benefits is hardly new. Ancient Egyptians, Greeks and Romans used cold water therapy for medicinal purposes and for relaxation. Today, ice baths are most typically associated with professional athletes, but if social media is to be believed the practice is gaining popularity among musicians, celebrities and fitness influencers. So what’s the deal? Can doing something so uncomfortable really be good for you?
Potential Benefits of Cryotherapy
Pain Relief
Anyone who has twisted an ankle knows the drill: Ice and elevation are the best ways to treat an injured muscle. Under that theory, an ice bath could help alleviate bodily aches and pains. When you take an ice bath, your blood vessels constrict, which can help to reduce swelling, pain and inflammation. Some research has shown that when cold water hits cold receptors on your skin, it sends electrical impulses to the brain that have a pain-reducing effect.
This is why professional athletes have long relied on ice baths to help reduce muscle soreness. Essentially, the way our body builds muscle is by stressing the tissue, which creates tiny micro-tears. We “build” new muscle every time our body works to repair those tears — but it’s also why we feel sore after a difficult workout. A review of 32 randomized controlled trials found that cold-water immersion one hour after exercise helped reduce muscle pain and improve muscle recovery for up to 24 hours by limiting the inflammatory response. (Interestingly enough, heat therapy had similar results.)
Many patients who suffer from rheumatoid arthritis similarly rely on forms of cryotherapy for pain relief. A 2022 study found that, compared to a control group, a group undergoing whole-body cryotherapy had significantly reduced rheumatoid arthritis pain. The whole-body cryotherapy group also had lower pain levels at its 12-week follow-up. However, this study only involved 56 test subjects — a tiny sample size.
Almost every study we found included a similar caveat: While ice baths anecdotally seem to relieve pain and inflammation, a lot more research needs to be done to ascertain the whys and hows.
Mental Health Benefits
Ice baths and cold plunges seem to be experiencing newfound popularity — at least on social media — not for their effects on the body, but on the mind.
It doesn’t feel good to immerse yourself in cold water (or at least, not at first). Every cell in your body screams with an ancestral instinct to get out. You may feel sharp pain. Many experience difficulty breathing. But some people believe that you can gradually overcome these physical discomforts using mindfulness techniques — and that by doing so, you become better at coping with different forms of stress.
Ice baths stimulate the part of the nervous system that regulates the fight-or-flight stress response. Partaking on a regular basis under controlled conditions may dampen that response, almost like a form of exposure therapy (pun intended). Research has also shown that cold plunging increases the concentration of dopamine — the “feel good” chemical — in the brain by 250%. Plus ice baths reduce the amount of the stress hormone cortisol. So theoretically, over time ice baths can help you become more resilient against stress.
Potential Risks of Cryotherapy
Unsurprisingly, some serious risks can be associated with ice baths and cold plunges. The severity of potential side effects depends on various factors, such as your health, time spent in the water and temperature.
Hypothermia
For a healthy person, the most common risk is hypothermia. The CDC warns that hypothermia (a dangerous drop in body temperature) can occur at water temperatures below 70 degrees. You can develop immersion hypothermia when submerging in water colder than 59 degrees; water moves heat away from the body 25 times faster than air, so hypothermia sets in more quickly underwater.
Some symptoms of hypothermia include clumsiness or lack of coordination, confusion, slow and shallow breathing, or a loss of consciousness, so you should never attempt an ice bath or cold plunge alone. The symptoms can set in gradually — so you may not even realize that you’re in trouble.
Cardiovascular Complications
The surge in the hormone norepinephrine released when you submerge in cold water (as part of the fight-or-flight response) increases your heart rate, blood pressure and breathing rate. For young, healthy people this has a temporary effect, but for anyone with a history of high blood pressure, heart disease or vascular conditions this could be deadly. If you have cardiovascular disease, the sudden narrowing of your blood vessels could lead to a stroke or other dangerous complications, so please be sure to check with your doctor before engaging in any form of cryotherapy.
Diabetic Complications
People with both Type 1 and Type 2 diabetes need to be careful with ice baths for a couple of reasons: They have a reduced ability to maintain core temperature during extreme temperature changes, and they are also more likely to experience peripheral neuropathy. The latter could prevent them from feeling dangerous coldness in their extremities, leading to damaged tissue.
How to Do an Ice Bath at Home
If you get the go-ahead from your physician, you can try cryotherapy at home in a bathtub or a portable plunge tub like this one. (If you don’t have a tub, a cold shower can be pretty refreshing, but it won’t deliver the same therapeutic benefits.) Have a friend or partner nearby to ensure that everything goes smoothly. Then, follow some of these comfort and safety guidelines:
- Acclimate using cold showers that are between 50-59 degrees and are generally safe.
- Continue acclimating slowly. Start with a bath using the coldest tap water setting. You can also start by immersing only part of your body at a time, like feet, then legs, and working up to your hips and chest.
- If the tap water temperature is above 59 degrees, you can add ice gradually. Most experts recommend ice baths to be between 50 and 59 degrees. It is important to use a thermometer because going too cold can be dangerous.
- Start with baths that last only 2-5 minutes. Slowly increase your time to no longer than 10-15 minutes.
- You can protect sensitive parts of your body by wearing a bathing suit or light articles of clothing.
- Try to relax, taking deep breaths if you can, as you soak.
- If anything feels wrong, get out immediately.
- When done, dry off thoroughly and warm up your body gradually. Some people do light exercise to get their blood flowing, like yoga or a brisk walk.
At top: Image by arissanjaya from Getty Images, via Canva.com.
