Extreme athlete Wim Hof, host of the BBC program Freeze the Fear, says there is “power in the cold shower.” Hof, who set a Guinness World Record for swimming under ice, says that a “cold shower a day keeps the doctor away,” according to Inverse.

Hof claims that cold showers benefit good health by decreasing stress and increasing energy. He asks celebrity participants on his television show to have a cold shower of 12 degrees Celsius or about 53 degrees Fahrenheit every day, increasing the duration of the shower from 15 seconds to two minutes. The guests’ reaction to the cold therapy tells a shocking tale.

One large study of 3,000 participants in the Netherlands found that people who took a daily warm shower followed by a cold shower of either 30 seconds, 60 seconds, or 90 seconds were 29% less likely to miss work with self-reported illness, according to Inverse.

Hof suggests that cold water improves heart function by training the tiny muscles in the cardiovascular system much like we train our larger muscles by going to the gym. When you take a cold shower, your heart rate and blood pressure increase, and there is some evidence that cold water activates the sympathetic nervous system, which triggers the “fight or flight” response.

Immersing the body in cold water can improve circulation according to one study that found cold water after exercise constricted blood vessels. When the cold water stopped, the body had to warm itself up. In doing so, the vessels increased in size allowing more blood flow. After four weeks, the blood flow to and from muscles improved.

According to Healthline, cold showers are defined as showers with a water temperature below 70 degrees Fahrenheit. While they are not a source of treatment for any condition, they may provide symptom relief and a sense of general well-being.

Taking a cold shower for up to 5 minutes, two to three times weekly may improve the severity and symptoms of depression according to one clinical trial. Cold showers can boost metabolism, which, along with a healthy diet and exercise, may help you lose weight.

Some people report that their skin looks better after a cold shower, and athletes have long known that cold showers help heal sports injuries, says Healthline. It’s the same mechanism as using ice to reduce inflammation when we bruise or tear a muscle. By reducing body temperature in that area, warm, oxygenated blood flows to that spot. People with poor circulation, high blood pressure and diabetes may benefit from cold showers.

Cold showers may also help ward off common illnesses such as colds and flu. The shock of cold water to the bloodstream stimulates leukocytes that fight infection in the body.

Experts warn that cold showers are not a form of treatment on their own, but could be used to supplement traditional care. People taking medications for mental health should not stop taking their drugs in favor of an alternative treatment.

If you are feeling ill, are immunocompromised, or have recently been hospitalized, wait before you try cold shower therapy. Experts suggest easing into the habit once you start by making the water temperature a little uncomfortable and staying in the shower for only several seconds. Next time, make the water slightly cooler and stay under for another minute or two.

After practicing for a while, you may start looking forward to your healing, cold showers.