It strikes many as simply unpleasant, but there are a significant and growing number of people willing to invest in the experience of rapidly cooling their body.
There's a very low end of this market; one can achieve the same conditions cheaply with a few bags of ice from 7-Eleven and a 55-gallon tub. And social media is replete with DIY schemes, some that involve chest freezers, heat pumps in reverse, and the like. And there's a midrange product that roughly mirrors portable spas, only cold.
In this story, however, we're talking about the elite segment of the market, where installations look a lot like custom spas.
All these people, regardless of outlay, want to produce the same effect — a sudden rapid loss of body heat. And they're not looking for a refreshing plunge into a fairly chilly (by my standards) 65-degree cocktail pool after sweating in a sauna or hot tub. They're after something in the low 40s, which is much different and much harder to achieve.
The payoff, the source of excitement about the experience, has to do with human physiology. When the body warms up through exertion or by sitting in a sauna, it tries to throw off heat by sweating and rushing blood toward its skin and extremities where it can be cooled by ambient air and drying moisture.
If one then jumps into a vessel of ice-cold water, blood reverses course and heads for the body's core to preserve warmth. That phase is very unpleasant, admits Ben Lasseter, enjoyer of such activities, and also Watershape University instructor and director of construction at Design Ecology, an award-winning Landscape Architecture and Luxury Pool Design/Build firm based in Austin, Texas. But here's the payoff, he says, "When you get out, you get this rush of blood back to your extremities. It's almost like an explosion of blood flow after the restriction you had. It's like opening the floodgates. All of a sudden, you've got this relief and a lot of really cool things happening to your body.
"The first time I tried it, it was a fight. I had to hold onto metal bars and push my body down with my arms because the rest of my body was trying to get out of there. I'm fighting to stay in for 30 seconds. And when I get out, it's pain initially, but it's like that good athletic pain. It's pain, but you know there's gain coming. It takes a few minutes for your feeling to come back, but it's semi-euphoric. You feel really, really good. Your brain is clear. You think better, you're sharper.
"And instantly I said, 'I know why people are addicted to this. I know why people want this.'"
People Want This
Cold plunge began creeping through the culture, like a deep chill, sometime in the mid-twentyteens. Michael Abdo, project manager at J. Tortorella Swimming Pools on Long Island, remembers designing his first cold plunge when he started with the company. "That was six years ago. It grew from there, and it's trending on TikTok now. I'm not sure why, but it is.
"Now, we get calls from homeowners who might have seen this at a friend's house or one of their country clubs, and they'll say, 'Oh, I was at this spa, and I loved the one they had. I want one exactly like it.'"
Customers include professional athletes (which now includes college athletes), wealthy fitness enthusiasts, health clubs, spas and more, who use cold plunge as a tool to speed recovery after intense workouts. They're looking for a permanent aquatic space that can maintain a temperature just above freezing and look beautiful at all times.
Vision Pools, based in Los Cabos, Mexico, designed and built this stately and inviting cold plunge along the coast, with warm views to complement frigid bathing.
The Installation
Aesthetics are essential in these installations, and they mirror the materials and construction techniques of custom spas. Elite cold plunge pools are often built out of concrete and tile, but on occasions, a manufacturer like Diamond Spas or Bradford Products will manufacture a vessel out of stainless steel or copper, as they do for hot tub builders. "I ran into a guy here in Austin the other day who fabricates them out of exotic woods," Lasseter says. "He doesn't do the mechanical part, he just does the woodworking part. The builder gives him a drawing and says, 'Hey, this is what we want it to look like,' and he makes it out of fine wood."
The functional side — how to produce and maintain very cold water without appearing to do so — is more challenging. "It's trying to get it to fit in with what they have," says Tully Gould of Corby Pools, Mountain View, Calif., a company that builds custom cold plunge in the bay area. "Maybe they already have an attractive pool and a spa. Well, the cold plunge needs to match that. And you need to figure out where to put the equipment so that it's not an eyesore."
The mechanicals themselves are crucial in their own right. An operational system needs airflow at the heat exchanger, plenty of power, and a way to circulate the refrigerant. Most of all, Gould says, "You need to size them properly, otherwise they'll underperform."
The big thing to avoid is an underpowered unit. The cold plunge has to keep a large temperature differential — perhaps as much as 70 degrees for an outdoor unit in a hot Sunbelt state. If there's either too much water or too little power, it will really struggle to cool down, as will the customer.
So size matters greatly. Typically, custom cold plunges are smaller in volume than say, your average custom spa, for two reasons: 1) It takes more power to maintain the temperature differential, and 2) You're not really looking to hang out and party in there with your friends, you're just enduring discomfort. So all you really need is immersion.
"Yeah, there are diminishing returns as you start getting bigger and bigger," says Lasseter. "We worked on one that was a 36-inch cylinder with no benches. It just had climb out rungs, like foot rungs and a ladder. I think it was only something like 175 gallons, really small, the most efficient use of space that you could have for that."
"And for a commercial unit, a typical cold plunge that you would see in a spa situation or a hotel situation, where you go and you pay money, and they massage you and you do the hot/cold — one of those is 250 to 500 gallons. They're not very big."
Jumping in Head First
The builders interviewed for this story are experienced in planning and constructing custom spas and pools, but all of them recently took their first dive into cold plunge. "The first one we did — you want to talk about jumping in headfirst?" says Lasseter. "The customer wanted 4,500 gallons. That's about 10 times the size of a normal cold plunge you would find in a luxury therapy suite. That was our first one. They wanted that enormous size so it would match the spa, to fill the aesthetic role."
Such a gargantuan cold plunge would require an equally humongous piece of machinery and everything that goes with it, such as power draw, noise, weight, displacement, etc. This presents an engineering challenge when you want the equipment to maintain a low profile.
"We didn't want a massive chiller going at a 100% all the time," Lasseter says, "so we decided to do two medium-sized chillers that could work at 50, 60% of their capacity.
"That way, if there was ever an issue with one, the other one could pretty much do all the work by itself. And that's important to this client because it's not his first home. And if he's traveling and something goes wrong with the unit, he may not know it or staff may not catch it because nobody's using it every day. So having that redundancy was important because when he flies into town, he's going to want the cold plunge ready for his swim."
This installation from Vision Pools provides access from both sides along with tiered seating, which allows users to choose a comfortable depth in the icy water. The charming natural water feature above offers both visual and audio enhancement to the cold plunge experience.
Essential Communication
Like most any project, Lasseter's installation was successful due to thorough communication with the client. With cold plunge being such a new and niche product, that's even more crucial than usual. Essential questions include: What temperature do you want? Do you want to maintain the temperature at all times, or are you going to turn it on for a weekend and turn it off? Is this something that you want to be sitting down in or do you want to stand up? How tall are you?
With all the measurements and details in hand, Gould says, his company lets the engineers at American Chillers, a design and manufacturing company in Columbia, S.C., deliver the equipment.
"American Chillers helps specify everything, because we have to make sure that we are getting all of our parameters right on the design side, and make sure that we can maintain the temperature that the client wants, because everything needs to be calculated and factored in. We give all the details to American Chillers, and they'll size a unit for it. We just send them measurements like how many feet of pipe, ambient temperature, all that, and the structure of the tub, they build it to order."
Congruent shapes and a pale blue Pacific backdrop turn this cold plunge from Vision Pools into a work of art.
Fabulous Future, Or Just A Fad
Builders considering adding custom cold plunge to their lineup of offerings, and retailers thinking of putting portable cold plunge in their stores have to ponder the future of the movement. We may be at a great inflection point in the growth curve of cold plunge. Its popularity could continue to gain momentum; cold plunges could become as commonplace as spas and gas grills. Or the whole thing could fade to obscurity. Right now, the market is growing at all levels.
The DIY segment of the market, which can be observed on social media, is the most amusing. "I've seen fish tank chillers, stock tanks," says Gould, "giant Rubbermaid containers with a refrigeration unit attached. The water's so cold, you hardly need to filter it or put any chemicals in it. It only takes a tiny little bit of chlorine to keep it clear, nothing grows in it, and you're only spending a couple minutes in there, so it doesn't need to be big."
In the middle of the market is something roughly akin to a portable spa. "You've got the person who's wanting to spend two to $10,000," says Lasseter. "They can get something entry level, install it themselves, plug it in, and a day later, you've got cold water.
"And that's a huge market right now. It's not the market that I sell in, but it's a good market. We charge eighty-five to a hundred thousand minimum on our custom installs. Our average is probably $150,000."
But there's a lot involved at the high end of the market. For those entering that space, says Abdo."It's a bigger challenge to do the custom plunge pool. Just making sure they have enough space for the equipment and making it fit aesthetically, because most of the time it's going to be a pool, spa and plunge pool close to each other."
On the other hand, Gould has rarely seen such enthusiasm for any product. "People really want these pools," he says. "I've yet to have anyone say they never use it. Our customers that buy these plunge pools — they really love them."
This article first appeared in the November 2024 issue of AQUA Magazine — the top resource for retailers, builders and service pros in the pool and spa industry. Subscriptions to the print magazine are free to all industry professionals. Click here to subscribe.
