HMN 2025: How to take the plunge in icy waters

As you prepare for that annual icy plunge into a lake, river, or ocean, Dr. Chris McMullen has this advice: Enjoy the water for a few minutes, with as many people as possible. So get out. Warm.

“Don’t go off on your own, don’t go through the ice or jump in,” said McMullen, a UW Medicine rehabilitation physician who specializes in sports medicine. He also suggests checking with your doctor first if you have any underlying conditions.

New Year’s Day will see gatherings large and small emerge from the heated comfort of their cars, shed their heavy coats, shirts and pants and wear only swimsuits and towels to combat the cold.

Some come to wash away the old year and jump or splash into the new. Others come to enjoy the reported health benefits of a cold bath, which range from reducing blood sugar to alleviating depression.

Cold water immersion has been well-studied in athletes and has been shown to reduce physical pain, McMullen said. But jumping into the bay once a year is another matter.

“Health benefits have been proposed as to how it could help someone with their mental health and their physical health,” he said. “Some of the potential benefits include reducing stress (and) reducing anxiety. Some think it could help regulate blood sugar.”

It’s possible that cold dives boost immune system health, he added.

“Repeated immersion in cold water has been shown to increase the circulating concentration of certain immune system cells and proteins,” McMullen said. “The limited studies we have on the health benefits of cold immersion suggest that people who do it more repetitively may see more of these benefits.”

That said, McMullen stresses that people with a history of heart problems, high blood pressure, hypothyroidism, and Raynaud’s phenomenon (where blood flow is severely restricted to the hands or feet) should consult their doctor before taking the plunge. in the polar adventure.

When it comes to annual divers, the research comes down to thin ice.

“There may be some benefits, but we need to study this a little more,” he said.

McMullen nevertheless encourages people to try, with some caution.

“As harmless as it may seem, in some cases immersion in cold water can be dangerous,” he said. “We know that people are more likely to drown in colder water than in warmer water.”

There is a physiological response to such immersions called “cold shock” it can affect the heart and blood pressure. Your heart rate increases. Stress hormones increase. You suddenly gasp and may breathe irregularly. Then you start to shiver.

The body tries to keep its body and core warm, McMullen said. Peripheral blood vessels constrict to carry blood to vital organs. This can increase heart rate and blood pressure and cause the release of hormones and neurotransmitters like cortisol, dopamine and adrenaline. All of these physiological responses occur almost immediately, McMullen added.

Only stay in the freezing water for a few minutes, McMullen stressed, especially if you’re new to it.

More and more people have embraced the idea of ??diving into cold water in recent years. Thousands of social groups report doing this on a weekly or daily basis.

“We’ve really seen this kind of explosion on social media and influencers promoting these potential benefits,” he said. “It’s a little surprising how popular it’s become.”