Go for the Sweet Spot: Rethinking Constrast in Thermal Wellness

Multiple-temperature pools help guests find their cooling "sweet spot." Photo: Tierra Santa Healing House at Faena New York by Nikolas Koenig 

Cold plunges may be having their moment, but effective contrast therapy does not need to be a test of endurance.

In this article, originally published on LinkedIn, DFL CEO Don Genders explores how cooling can be designed to deliver meaningful contrast without pushing every guest toward extreme temperatures. He also looks at the importance of providing different cooling options, the operational realities of commercial cold pools and why the best experience is often the one guests will want to repeat.

The Shift Toward Simplicity and Authenticity

I am seeing a real shift in the wellness industry toward simplicity and authenticity. This has been obvious in the way younger generations approach body and face treatments. There is a growing focus not only on the provenance, ingredients and sourcing of the products used, but also an awareness that traditional treatments rooted in centuries-old practices are often more effective than something newly created to promise a specific result.

Guests are more questioning now. Put simply, they are less willing to accept a claim simply because it is wrapped in luxury language.

I am also seeing a growing acceptance of a no-frills approach to just about everything in the spa and wellness world. Yes, there will always be those seeking the fountain of youth or the promise of longevity, but wellness seekers, both young and old, seem increasingly interested in finding what truly works for them rather than chasing the latest trend or promise.

In thermal wellness, this shift is especially clear in the cooling conversation.

If you need a cold shower after a sauna, you take a cold shower. You may grit your teeth and bear it for 60-90 seconds because you understand the purpose. You do not necessarily need an “experience shower” with changing lights, storm sounds, fake rain or injected aromas to entice you to use the shower and keep you there long enough for it to be effective.

There is nothing wrong with sensory design when it is done well. But the most important part of cooling is not the theater, it’s the contrast.

Often overlooked, foot baths and foot showers offer an approachable way to cool down or warm up the body during a thermal bathing journey. Photo: Dornbracht

For the last few years, cold plunges and ice baths have dominated the conversation around contrast bathing. I’ll admit, some of that attention has been useful. It has introduced a much wider audience to the value of moving between heat and cold.

When Cooling Became a Performance Sport

But the conversation has also become distorted. It has been weighted heavily toward aspirational freezing temperatures – from TikTok videos of ice-hole bathing to Wim Hof techniques and endless commentary around extreme cold exposure. Then there are those replicating what they see in elite sports: athletes turning to ice baths after 60 or 90 minutes of high-level training or competition.

I often have to remind people who come to DFL that the general public is not made up of elite athletes or Wim Hof devotees.

Contrast is Not Punishment

Most guests are not trying to prove they can endure the coldest possible water. They are people who want to take better control of their wellness. They want to recover, reset, sleep better, reduce stress, strengthen resilience and feel good enough to come back again.

The goal of cooling in a hydrothermal circuit is not punishment. It is contrast. And contrast does not mean pushing the body to the most extreme edge.

The Sauna Analogy: Just Because You Can Doesn’t Mean You Should

We understand this instinctively with saunas. A sauna may be capable of very high temperatures, but that does not mean it should always be operated at its maximum. Nobody drives their car at the maximum speed simply because the engine can do it.

Saunas can be heated to very high temperatures, but most operators and sauna owners choose a range that works for their guests. The goal is not to prove how hot the room can get. The goal is to create the right bathing experience.

Cooling should be approached with the same common sense.

Just because a chiller can bring water close to freezing does not mean that is the right operating temperature for a commercial cold pool. Many cold plunge products sold online promote extremely low water temperatures, and operators can feel pressure to match that expectation.

If a cold pool is so cold that most guests avoid it, what has really been achieved?

Cold Pools, Water Quality and Operational Reality

There is a well-established range in European thermal bathing environments where cold pools are cold enough to create meaningful contrast, but not so extreme that only a small percentage of people will use them comfortably. In my experience, that range is often around 10°C to 15°C / 50°F to 59°F, with 12°C / 54°F often sitting in the sweet spot.

Cold enough to do the job, but not so cold that it becomes a stunt.

This is where I think the industry needs to tread carefully. If we want people to return again and again, we need to design experiences they can understand, tolerate and enjoy. There is no long-term value in creating a feature that people try once for a photo and then avoid.

There is also a practical design and operational question here.

A great deluge shower with icy water can be extremely effective. A properly designed cold pool can also be a very strong cooling experience. But small bathtub-style cold plunges are not always the right answer in commercial settings.

Deluge showersdeliver an intant cool-down after heat, creating a simple but powerful moment of contrast. Photo: Civana Resort, Carefree, AZ

They may look simple, but they can be incredibly difficult to manage from a water chemistry and hygiene standpoint because of the high bather-to-water-volume ratio. And, with more people choosing cold water experiences, this becomes more important, not less.

A larger cold pool can often make more sense.

The higher water volume means hot bodies have less impact on increasing water temperature. The water management system is easier to control. Guest safety and hygiene can be better supported. And there can be a significant financial impact in replacing multiple small pools with one larger pool, because every separate body of water needs its own filtration system.

This is not just a wellness preference. It is an operational reality.

Verify What We Repeat

The cold plunge conversation has also created a lot of debate around the “right” temperature. Some of this debate is useful. Safety and guest education matter, but not every claim circulating in the industry is well supported, and operators should be careful not to make decisions based on panic, social media shorthand or poorly understood data. One recent example is the widely repeated claim that women should not bathe in water below 15°C / 59°F. I have found little credible support for this claim, yet it has created unnecessary concern among operators and guests.

We need to verify what we repeat and to ask whether the guidance we are following is based on credible science, real-world use and sound operational practice — or whether it is simply being repeated often enough that people assume it must be true.

The same common sense applies to warm water.

Gentler Cooling Has a Place

We are also seeing hot pools being eclipsed, in some cases, by temperate pools. If you only have room for one warm pool, a hot pool may still appeal to more guests. But where space and budget allow, a temperate pool can be a very valuable part of the circuit.

A pool around 26°C / 79°F is not extreme. It is close to competition swimming pool temperature. But it is below body temperature, which means it can offer a very good, gentle cooling experience. It gives people another way to cool down without shock, and it can help make the circuit more accessible to a wider range of guests.

Better Choices, Not Colder Water

The industry does not need to abandon cold plunges. Far from it. Cold water has an important place in thermal wellness. But we need to move beyond the idea that the coldest possible option is automatically the best one.

Our goal should be understanding what the body needs after heat, and designing that experience in a way that is effective, safe, repeatable and commercially sensible. And then educating guests on the best way to use it.

If you build it and they come, the aim should be to make as many of them as possible want to come back again.

Go for the sweet spot.

This article was originally published on LinkedIn