As Texas temperatures rise, a cold plunge sounds as appealing as a Willie concert on the 4th of July (that’s real good!). But is cold water immersion (CWI) just a way to cool off from sidewalks so hot they could fry an egg? Or are there really health benefits? 

Data from clinical trials, university research, and anecdotal evidence suggests that this recovery trend is more than Wim Hof woo-woo. Here’s why cold plunging (scientifically referred to as “cold water immersion”) earns a Landman-sized “yee-haw.” 

Cold Water Immersion History

Cold water immersion is nothing new. Cold application was used for treating skin irritations as early as 3500 BCE in ancient Egypt. This was documented in the Edwin Smith Papyrus, once the oldest medical documents known. Hippocrates, the “Father of Medicine,” used cold water immersion for medicinal purposes and relaxation in 400 BCE ancient Greece. Athletic trainers have been prescribing ice baths since the 1960s. (It became mainstream for post-exercise recovery and injury treatment in the 1970s.) “R.I.C.E.” stands for rest, ice, compression, elevation. The “RICE” method is the least-invasive prescription for treating acute injuries. The “i” in RICE can be modified to cold water immersion. Nowadays, many people are passing on messy ice packs and treating acute pain with cold plunging. Care of athletic injuries and post-workout muscle fatigue are part of the reason for the rise in the nascent cold plunge trend. That’s where we’ll start. Recent studies have revealed mental, emotional, social and somatic benefits. We’ll plunge into those, too.

Muscle Repair, Inflammation Reduction and Pain Relief

Cold water immersion can reduce the degree of exercise-induced muscle damage. Here’s what that may mean to you. Let’s say that you do leg day with heavy squats, deadlifts, and lunges. But you need your legs fresh for a Hyrox competition two days later. (Hyrox is the fastest-growing elite sport craze in the world.) If you submerge the limbs that were taxed in “leg day” in a cold plunge after your session, you can decrease delayed-onset muscle soreness. (I may put this actual scenario to the test when Hyrox returns to Dallas in November.)

CWI is most effective immediately after the workout. (Don’t poke around, grab a protein shake, check Instagram and call your mom. Get in the cold plunge right after your strenuous workout.)

Why does cold water immersion work for reducing muscle damage right after an intense workout sesh? The blood vessels are constricted and blood flow to the areas submerged under the cold water is decreased. This is called vasoconstriction. Vasoconstriction causes reduced inflammation. Inflammation is a cause of pain in joints and tissue. While in the cold plunge, pain in areas burdened by inflammation will lessen or go away. Your heart rate (HR: beats per minute) is decreased and stroke volume (SV: how much blood is pumped per systole) is also decreased. Cardiac output, therefore, is decreased, because cardiac output= HR x SV. Any time cardiac output is decreased, blood pressure and blood flow will also decrease.

Fight or Flight then Rest and Digest

It may be confusing whether cold water immersion stimulates the energy-jolting sympathetic nervous system (“Aaaaah! This is shockingly frigid!”) or the parasympathetic nervous system (“Ahhhh! This is peaceful.”). Well, it’s both. 

When you plunge your body into the water so cold that it’s nearly at freezing point (but not quite), your autonomic nervous system connects your brain to your body and sends the message “fight, flight, or freeze!” The instant stress stimulates the sympathetic nervous system. That is not a bad thing for healthy individuals. (If you have heart disease, talk to your M.D. before CWI.)  The energy boost from that sudden shock to your system triggers a release of dopamine, serotonin, and noradrenaline. Dr. Susanna Soberg, who completed her PhD in metabolism and cold water exposure, found in her research that dopamine and noradrenaline can increase up 2.5 fold in just a few minutes. 

As you stay in the frigid water, blood flow and blood pressure to the areas of the body exposed to cold water will decrease and those body parts benefit from an analgesic effect. The nervous system literally chills out and activates the parasympathetic nervous system. (If you adopt a practice of cold plunging regularly, this shift to parasympathetic activity happens pretty quickly.) The parasympathetic nervous system stimulates the vagus nerve. When blood flow is restricted from other areas, blood flow is redirected to the brain. The brain rallies the vagus nerve to slow down the heart rate. The vagus nerve flows from the brain to the back of the neck, through the chest, and down to the large intestine (hap-py gut do do, do do do do 🎶). It sends a relaxation response. Anecdotal stories you hear from friends who swear that cold plunging has helped them find peace, calm, better sleep and improved mood are almost certainly referring to the relaxation effect of stimulating the vagus nerve. 

Research highlights an intriguing finding that cortisol levels don’t significantly change during cold water immersion, but they significantly decrease afterward! This study revealed that participants who participated in cold therapy for two minutes, three times a week for twelve weeks measured a significant drop in cortisol post-cold exposure immediately after the first four weeks, with levels continuing to drop in the following weeks.

Female Considerations

When looking at women’s-specific response to CWI, Stacy Sims, Ph.D. found that cortisol does, in fact, rise during cold water immersion for women. In a now viral podcast, Sims stated that the plunge invokes a stronger, more severe stress response than a male’s response and mightily activates the sympathetic nervous system. Dr. Sims advocates that, for women, “All the positives of cold water immersion still apply, but the caveat is the temperature.” Dr. Sims recommends 15 degrees Celsius. (To translate that to Texan, that’s upper 50s.) 

A slightly different approach, Dr. Susanna Soberg advises that women adjust the temperature of the cold plunge when they are more sensitive to stressors. “Women really need to listen to their bodies during their cycle,” says Soberg. “They don’t need to go to a specific threshold all the time.” She advises that women adjust the time and temperature of the water depending on their sensitivity. “The definition of ‘cold water’ as per activating your cold shock is 15 degrees. 19 degrees and below is fine.” That’s not bona fide “cold water,” but in her research, 19 degrees Celsius is cold enough to activate brown fat. (19 degrees Celsius is 66 degrees F.) Dr. Soberg champions that a quick dunk can deliver health benefits, but that the rapid shock will only stimulate the sympathetic nervous system. For parasympathetic activity, aim for two minutes or longer. More below in How to Start a Cold Plunge Practice.

Immune System Support

Cold plunging may dial up your body’s natural defenses. Some studies have shown positive effects of cold water on immune function. The number of white blood cells we have in our bodies boost our ability to fight illness. Regular cold water immersion may increase the number of white blood cells in our bodies, as suggested in the study linked above. A process called autophagy, where cells break down toxic proteins and recycle their old components, is desirable for health and immunity. (Autophagy is the reason why intermittent fasting is so popular!) This new study suggests that cold water immersion may be advantageous for autophagy. Human biologist, biohacker, and longevity researcher Gary Brecka often doubles down on the power of cold plunging to enhance immune function on his top-rated health and fitness podcast, The Ultimate Human.

Healthy Social Connection

A national survey conducted by Harvard Graduate School Students (Making Caring Common Project) in 2024 suggests that 21% of American adults feel lonely. Digital devices are fool’s gold. Social media should not be conflated with social connection. With concepts like Bathe, a communal bath house for social cold plunging, coming to Austin (Spring 2026) and luxury health clubs like Life Time converting communal hot tubs to cold plunges, it’s clear that there’s a social wellness benefit of coming together, putting our handy dandy cellphones down, and collectively exploring the benefits of the brrrrrrrrr.

“Cold water therapy is an evidence-backed method for enhancing recovery and mental resilience,” says Danny King, Life Time’s Director of Recovery and Performance. “Just getting started with small amounts of time in a cold plunge can increase energy and lead to more restful sleep. Our cold plunges are also a perfect complement for Life Time’s growing recovery offerings for our members’ health.”

Doing Hard Things Beget Doing Hard Things

Even if this is the first you’re learning about cold water immersion, you already knew this next benefit. (You just may not have known that you know.) Doing hard things begets doing hard things. Our brain perceives how difficult tasks are based on the data we give it. When we place our bodies in cold water, we learn to endure something uncomfortable. The longer we stay in the water (to a limit), we get comfortable with being uncomfortable. That teaches our brains that we can approach and take action on difficult tasks. That oh-so-vital organ then gives the go-ahead to do other hard things because of the validation that was established by approaching, taking action, and successfully completing a cold plunge.

How To Start a Cold Plunge Practice

For starting a cold plunge practice, set the water temperature to mid-50s. As the nervous system acclimates to the routine, gradually drop by 1-5 degrees. One to five minutes should be an ideal time spent in the plunge. There is a point of diminishing returns. Make 10 minutes tops to avoid the dangers of hypothermia. Women may opt to dial up the temperature a few degrees, as noted in the Fight or Flight section of this article.

Longer is not better with cold water immersion. You may risk cardiovascular implications. You can put your internal organs in danger. The nerve endings can get numbed to the point where you cannot get up. Hypothermia is undesirable. All benefits from cold water immersion can be reaped in single-digit minutes.

You may start your cold water exposure by regionally dipping only certain body parts, for instance, only sitting waist-deep in cold water. Studies have shown that submerging the neck in the cold water will best stimulate the vagus nerve. Maybe not on your first trip to the cold plunge, but before the cows come home, get adventurous and try a full dunk in the cold plunge.

Older populations, those with heart disease, those on certain medications, and those with low body fat (people with low body fat lose heat quickly) may need to make modifications or avoid CWI, altogether. If any of these special populations describe you, talk to your medical doctor before cold plunging. 

Where to Get a Cold Plunge

For an easy, portable, affordable cold plunge, we like the Echelon Smart Cold Plunge (1.0 HP). It is a two-piece system: a chiller unit and military-grade canvas tub. This product can chill as low as 36 degrees or heat as high as 104 degrees. The chiller unit can be turned on and off manually, or scheduled remotely with a connected app. Use the discount code PFP500 to take $500 off the price of this product. (Neither your author nor Texas Lifestyle Magazine profit from the use of this discount code. It’s a perk we worked out with Echelon to drop the price to you as low as possible so that you may experience the benefits of cold water immersion.)

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Cover Photo courtesy Brook Benten

Brook Benten, M.Ed., ACSM-EP  Brook Benten is an exercise physiologist, personal trainer, and life coach based out of Austin, TX. She has authored three books, including a memoir, “Sweat with Brook Benten,” and well-being book, “10 Minutes to Slim & Sober.” She is an avid trail runner and triathlete. Brook is the host of the More Than Sweat podcast and a recurring guest on the Tri Swim Coach podcast. IG @BrookBenten