What is cold therapy? Ice bathing explained

How does cold therapy work?

As soon as the body is exposed to cold water, it responds with a range of physiological processes. First, the blood vessels at the surface of the skin constrict (vasoconstriction) to keep body heat in the core. The nervous system switches into a so-called “cold shock” mode: breathing rate and pulse rise briefly, and stress hormones such as noradrenaline are released. As the body then warms up, the vessels widen again (vasodilation), so that more blood – and with it oxygen and nutrients – flows into the previously cooled tissue.

This interplay of tension and relaxation is described in research as a mild, controlled stress stimulus – a principle known as “hormesis”: a short, manageable stimulus can prompt the body to adapt and, over time, become more resilient. In addition, the activity of brown adipose tissue, which plays a role in the body’s own heat production, is stimulated.

Where does ice bathing come from? A look at its history

Using cold water is not a new invention.

1. For centuries

   Avantouinti in Finland

   Plunging into icy lakes after a sauna session – “avantouinti” – has been part of the culture there for centuries.

2. To this day

   Misogi in Japan

   Buddhist and Shinto traditions still practise “Misogi”, a ritual cleansing bath under cold water or waterfalls.

3. 1970s

   First cold chambers in Japan

   The first cold chambers for controlled whole-body cold exposure were developed, and modern cryotherapy grew out of them.

4. Today

   A wide audience

   What was once a ritual and a medical niche has become known to a wide audience through athletes, biohackers and wellness enthusiasts.

Benefits of cold therapy: what the research shows

Cold therapy has been increasingly studied in sports and health research for several years. In many areas the evidence is still young and not conclusive – but for several topics, recurring observations are emerging. The following points summarise the areas in which controlled cold exposure is most often studied.

Helsi™ products are not designed to diagnose, treat or prevent any disease. The points above summarise the current state of research and are not medical promises. If you have an existing health condition, please speak to a doctor before use.

What is cold therapy used for?

• Recovery after training: Many athletes use cold after intense exertion as part of their recovery routine.
• Mental clarity and focus: The short, intense stimulus demands conscious breathing and concentration – an effect many describe as a “reset for the mind”.
• Starting the day with energy: A short ice bath in the morning is often used as a wake-up boost, similar to a cold shower, only more intense.
• Mindful handling of discomfort: Deliberately enduring an unpleasant but safe stimulus is valued by many as an exercise in composure and self-discipline.
• Part of a contrast routine: Combined with heat applications such as in a sauna or infrared sauna, an alternation of heat and cold arises that many find particularly harmonious.

Helsi™ products are not designed to diagnose, treat or prevent any disease. The points above describe how people build cold therapy into their everyday lives – they are not medical promises.

How to start safely with an ice bath at home

How could you begin? The simplest way is to hold your hands and feet in cold water to expose your body to the stimulus of cold.

Temperature

10–15 °C

To start with; later the classic 3–7 °C

Duration

30–60 sec.

At the start; experienced users often 2–3 min. Longer is not automatically better.

Frequency

2–4 a week

A common rhythm with a regular routine

Breathing

Calm

Controlled breathing helps with the first cold shock; do not hyperventilate

After the bath

Warm up

Let the body warm up naturally; movement or warm clothing support this

How an ice bath session goes

Start short and build up slowly. Breathe calmly and evenly, get out before it becomes unpleasant, and warm up actively afterwards.

How the Helsi™ Ice Plunge chills and stays clean

The integrated 1.5 HP compressor with environmentally friendly R290 coolant chills the water and makes ice automatically. Temperature is adjustable from 0 to 42 °C. Gentle water movement at 1.5 m³/h spreads it evenly.

Three stages keep the water clean: an ozone generator, a 20-micron particle filter and UV disinfection. Filters and the UV bulb are available as spare parts.

Space, power and weight

Overall 199.5 × 75 × 105 cm, the tub itself 144.5 × 65 × 85 cm. Empty it weighs 210 kg, filled 765 kg: the floor has to carry that.

It plugs into a standard 10 A socket with a 30 mA residual current device. Power is 1,400 W, noise below 70 dB, protection class IPX5. An insulated lid and a weatherproof cover are included.

• No fixed water connection needed.
• Delivered on a pallet: 215 × 87 × 120 cm, 280 kg.
• A cedar step is included.

Cold and heat in winter

In winter the ice plunge is often paired with heat as part of a contrast routine: first the Helsi™ One Sauna Dome, then the cold water, then warm up again. Leave enough time to warm up.