Ice bathing in summer: How cold, how long, and what it costs!

In summer, ice bathing becomes difficult: lakes and rivers are too warm, and you can hardly find any cold water in nature. At the same time, one heatwave after another rolls in, making it difficult to sleep at night. We'll show you why an ice bath at home is most valuable right now!

In this article, you'll learn how many days a year you can still ice bathe outdoors in Switzerland, what water temperature is suitable during hot weather, and when it becomes dangerous. You'll get specific location tips to ensure your ice bath stays truly cold in summer. Finally, we'll calculate why an ice bath at home is not an electricity guzzler after all.

At a glance

In an average year, Lake Zurich is above 15 degrees for around 122 days.
Swiss lakes only reach temperatures below 10 degrees, offering a true ice bath experience, from November to March.
During heat, 8 to 12 degrees is perfectly sufficient. Colder isn't necessarily better.
Electricity for an ice bath at home: It costs about 1 franc per day.

Eisbaden im Sommer

The Ice Bath Season: When Lakes and Rivers Get Too Warm in Summer

For ice bathing, you need water below 15 degrees. It only gets truly cold below 10 degrees. This is precisely what nature no longer provides in summer. Let's do the math for Lake Zurich:

On average, it's 18 degrees in June, 21 degrees in July and August, and still 16 degrees in September. That's 122 days above a possible ice bath temperature. The lake usually only drops below 10 degrees from November to March.

Lakes are getting warmer year after year

In 2026, it was even clearer. By the end of May, 26 of the 32 largest Swiss lakes measured their highest surface temperatures since records began. At the peak of the heatwave at the end of June 2026, Lake Zurich then reached around 28 degrees. That's bathtub temperature, not cold therapy.

And the mountain lakes?

Glacier streams and high mountain lakes remain at 8 to 10 degrees. Temperatures are not the problem here. However, the journey is often very long, so it often remains a one-time experience. Ice bathing in a mountain lake is a wonderful experience, but hardly feasible in everyday life. Because the important positive effects of ice bathing only develop with one to two applications per week.

So, ice bathing in a mountain lake rarely fails due to willpower, but rather due to a lack of practicality in everyday life.

Ice Bathing at Home: From Intention to Habit

An ice bath at home solves the problem in a simple way: it's always there when you need it. You don't have a long journey, no other appointment, no search for the right body of water.

"You go out onto the terrace and step in. Two minutes later, you're out again. That's it."

This sounds comfortable, but above all, it's the decisive factor for an effective routine that ensures all the health benefits of ice bathing.

How do I solidify a new habit?

The best-known study on this comes from Lally et al. They followed 96 people over twelve weeks as they built a new habit. The result: it took an average of 66 days for a new behavior to become almost automatic.

Crucially, it wasn't motivation that mattered, but a consistent context and a fixed trigger. So always in the same place, always at the same time. James Clear also describes this as a decisive factor in his book "Atomic Habits": shaping one's own environment.

If the desired behavior becomes as obvious and easy to implement as possible, you only need little discipline. An ice bath in the garden is a good example of a conducive environment. A mountain lake, two hours away, is the opposite.

Why regularity makes the difference

The effects of cold depend on repetition, not on a single ice bath.

In a randomized study with 3,018 participants, people took cold showers for 30 days. Their sick leave decreased by 29 percent compared to the control group.

Habituation to cold shock also requires repetition. A meta-analysis shows: after about four baths, the initial shock reaction measurably weakens. Breathing rate decreases by 27%, heart rate by 14%.

This effect lasts for a long time. Seven months later, it was still present at 31%.
Those who pause in summer start again from scratch in winter.

What Ice Bathing Does During a Heatwave

Eisbaden während Hitzewelle: Erfrischung oder Gefahr?

The heatwaves in summer 2026 are extreme. June in Switzerland was 3.5 degrees above the average from 1991 to 2020. In Western Europe, it was the warmest June since records began.

Basel reached 39.0 degrees, an all-time record for German-speaking Switzerland. Added to this were draining tropical nights.

Deeper sleep through ice bathing

A large study with over 7 million sleep recordings from 68 countries shows a clear correlation. If the night temperature is above 25 degrees, you sleep significantly shorter, and your deep sleep phase can be disturbed.

The reason is your thermoregulation. To fall asleep, your core body temperature must drop. In a tropical night, your body can barely manage this because it cannot dissipate heat.

A cold bath in the evening supports exactly this process. It not only lowers skin temperature but also internal body temperature, allowing it to lose more heat.

Ice bathing: how cold and how long in hot weather?

Here's the most important rule of the entire article: during a heatwave, you don't have to bathe at 3 degrees. Set your water to 8 to 12 degrees. That's perfectly sufficient for the refreshing effect. The difference to the outside temperature is already huge anyway.

How to proceed in hot weather:

Don't go directly from direct sunlight into the basin. Cool down briefly beforehand and relax in the shade. Avoid the midday sun.
After sports, wait 10 to 15 minutes until your pulse is normal again.
Enter slowly. First your legs, then hips, then slowly your upper body.
Keep breathing calmly. If you hyperventilate too much, get out.
Stay in for a maximum of 2 minutes, that's completely sufficient.

Important note: If you have a cardiovascular disease, suffer from high blood pressure, are pregnant, or are taking medication, talk to your doctor beforehand. This is especially true in hot weather, as your circulatory system is already under strain. Never go into cold water alone if you are unsure.

Eisbad Standort: Im Garten oder auf dem Balkon eisbaden

How to Keep Your Ice Bath Truly Cold

Our tubs are already well insulated with an 8 cm wall thickness. Nevertheless, there are simple ways to actively support your chiller in summer. Here's what else you can do:

1. The location is key

In summer, your chiller works against the sun. With the right location, you make its job much easier. Place your ice bath in a spot with sufficient shade. On the terrace under an overhang, in a garden spot under a tree, or with a large sun sail over the tub, because direct midday sun causes the greatest heat input.

Also pay attention to the ground. Dark stone and asphalt store a lot of heat and release it at night. A light surface or an insulating floor mat can also help. The chiller itself also needs shade. It works more efficiently if it is not standing in the sun itself.

2. The lid is your most important tool

Leave the lid on the ice bath whenever you're not bathing. Without a lid, heat can enter the basin quickly and unimpeded. Choose a light-colored basin, because white reflects the sun, while black absorbs it. You'll notice the difference significantly on a hot afternoon.

For the basin itself, wall thickness matters. Our basins have an 8 cm thick insulation in double-walled PVC tarpaulin. This keeps the cold in the water and means your chiller has to run less often. The hoses should also be insulated. The neoprene protection for hoses and filter is included in our set and should definitely be on in summer.

3. Optimal cooling times for “The ChillPro”

We recommend setting two fixed time slots daily, once in the morning and once in the evening, for example, 6:00 AM to 9:00 AM and 8:00 PM to 10:00 PM. That's five hours a day and is sufficient even in midsummer.

During this time, the ambient air is cooler, allowing the generator to work more efficiently. Additionally, water quality remains stable because the water is regularly filtered. Ideally, you should also bathe within these timeframes to benefit most from the low temperature.

You can set the time windows in the app's schedule, and then everything runs automatically.

How Much Electricity Does an Ice Bath Use?

Our chiller "The ChillPro" consumes 0.82 kWh per hour at maximum power. With five hours of cooling time, that's about 4.1 kWh per day. The average Swiss tariff in 2026 is 27.7 cents per kilowatt-hour. That makes 1.14 Swiss francs per day.

Eisbad Stromverbrauch berechnet - wie viel Strom kostet ein Eisbad pro Tag?

This saves even more electricity: the cooler stops automatically as soon as the target temperature is reached. After that, the water only circulates for cleaning. We are currently working on a new function that can circulate the water even without active cooling.

Conclusion: Good Reasons for an Ice Bath at Home

1. You can only ice bathe in nature for 5 months: On average, Lake Zurich is below 10 degrees for only about 150 days. In 2026, the natural ice bath season was already over by the end of May. Those who only bathe outdoors inevitably bathe irregularly or have to invest a lot of time.

2. Habits need a fixed place. On average, it takes 66 days for a behavior to become a firm habit, and that only with a consistent context. A tub on your own terrace provides exactly that.

3. Especially during heat, the cold stimulus is valuable. Night temperatures above 25 degrees cost you restful sleep. A cold bath in the evening helps your body dissipate heat for hours. And it only costs you about 1 franc per day.

Our clear recommendation: If you want to fully exploit the health benefits of ice bathing, get an ice bath at home. Not only because it's more convenient, but because it's the only way to stay consistent all year round.

Take a closer look at our "Ice Bath Complete Sets". With good insulation, including a chiller, and an optional 14-day free trial.

Ice bathing in summer: Why an ice bath at home is particularly worthwhile now