What Is a Cold Plunge? How It Differs From an Ice Bath and a Cold Shower

The ice bath: an immersion in water cooled with ice

An ice bath means sitting in a tub or bathtub filled with cold water, then adding ice to bring the temperature down. The ice gives the practice its name: without a machine, it is the only thing cooling the water. Temperatures often mentioned for an ice bath are around 50 to 59 °F. The amount of ice can be worked out (the physics is done in metric): melting 1 kg of ice absorbs 334 kJ, and cooling 1 liter of water by 1 °C takes 4.186 kJ. For 66 gallons of water, that means about 29 lb of ice to go from 68 °F to 59 °F, and about 61 lb to go from 68 °F down to 50 °F.

These figures are physical minimums: in practice, the air, the ground and the sun warm the water, so you need more ice. Two habits limit those losses: keep the lid closed between uses and add the ice just before you get in. An ice bath stays simple in terms of gear (a tub, water, ice), but you have to plan the ice for every session, especially when it is hot out.

The cold plunge: the same immersion, often with a machine

Cold plunge literally means a plunge into the cold. The act is the same as an ice bath: you sit in cold water, with your head above the surface. The difference lies mostly in how the term is used. Cold plunge often refers to tubs cooled by a machine called a chiller: an electric appliance with a pump that cools and filters the water continuously. The water then stays cold without any added ice. Yet the two terms describe the same immersion and largely overlap: a tub filled with ice can also be called a cold plunge.

The tubs designed for a chiller are mostly rigid inflatable tubs, known as drop stitch, of about 130 to 210 gallons, weighing about 35 to 42 lb empty. An electric appliance placed near water requires a suitable electrical setup, to be checked by an electrician. Before you buy, keep in mind that a tub designed for water and ice is not necessarily designed to take a chiller: the two uses do not call for the same equipment.

The cold shower: cold water, but not an immersion

A cold shower means standing under a stream of cold water in your usual shower. It is not an immersion: your body is not submerged in a volume of water, the water runs over you and then drains away. Its temperature depends on the water supply and the season, with no ice or machine to adjust it. Some people simply finish their shower with a few moments of cold water, others take it cold from start to finish: it is a matter of personal habit. No tub, no ice, no extra space: the bathroom is enough.

A cold shower and an ice bath are two different practices, and this guide does not compare their effects. They differ on concrete points. In the shower, you stand, you adjust the spray and you step out in one stride. In a tub, you sit with your back straight and knees bent, the water comes up to your shoulders depending on your height, and you have to fill, cool, watch over and then drain a volume of water. The routine, the preparation and the upkeep have almost nothing in common.

Ice bath, Eisbad, baño de hielo: the words in other languages

In English, the usual terms are ice bath and cold plunge, and the container is often called a cold plunge tub. In French, you will see bain froid, bain glacé or bain de glace. In German, you find Eisbad for the bath itself, Eistonne for the tub and Eisbaden for the practice. In Spanish, people say baño de hielo for the bath and bañera de hielo for the tub. In Italian, the terms are bagno di ghiaccio and vasca ghiaccio. All these terms describe the same thing: an immersion in cold water, most often with ice added.

In Italy and Spain, the word crioterapia is also used to name these tubs, simply as a category label. Here, the tub is never presented as a medical device or as a form of care: it is a container of cold water for a personal routine, nothing more. If you read a translated manual or compare tubs sold in another country, these words will help you recognize the same type of product.

What you need at home for each practice

For an ice bath, you need a tub and ice. The tub sits on level, stable ground that can bear the load: 87 gallons of water weigh about 730 lb, plus the weight of the person. On a balcony or an upper floor, ask your landlord, building manager or HOA what load is allowed. For a cold plunge with a chiller, you need a compatible tub, the machine, an outlet and a suitable electrical setup, checked by an electrician. For a cold shower, the shower you already have is enough.

On budget, public prices noted on September 28, 2026 give orders of magnitude by category. In the US, a round foldable tub sold on its own, without accessories, costs about $44 to $64. A rigid inflatable tub compatible with a chiller runs about $199 to $349, machine not included. Tub and chiller sets sit in another price range, about $649 to $1,099. On top of that come the ice for every ice bath session and the electricity for the machine. A cold shower requires no purchase at all.

• Ice bath: a tub, ice, water changed regularly, level ground that can bear the load, a place to drain the water.
• Cold plunge with a chiller: a compatible tub, the machine that cools and filters the water, an electrical setup checked by an electrician.
• Cold shower: the shower in your bathroom, nothing else.

Safety rules shared by every immersion

Ice bath or cold plunge, the rules are the same, since you are immersed in cold water. Before your first cold plunge, see a doctor if you have heart disease, high blood pressure, a heart rhythm disorder, a circulatory disorder (including Raynaud's syndrome), diabetes, epilepsy, are pregnant or are under medical treatment. Never take an ice bath alone: someone present and attentive stays close by. A British sea rescue organization points out that cold shock can occur in water at 59 °F or below: it takes your breath away and speeds up your heart. That is a reason to get in slowly, never an effect to look for.

The tub also calls for care when no one is using it. It is not for children: at home, the drowning risk also involves bathtubs, buckets and hot tubs. Close the lid when the tub is not in use, empty it when no one is watching it, and never leave a child near it without an adult. The Ice Bath Tub shop sells a single tub of this type, foldable, insulated and closed by a lid, as a complete kit (what's in the box: the tub and its 6 tubes, lid, dust cover, pump, cushion, drain, patches and carry bag), shipped free from stock in your region.

• Get in gradually and breathe calmly.
• Start short, 1 to 2 minutes, then build up gradually.
• Keep your head above water.
• Get out immediately if you feel dizzy, have chest pain, feel numb or start shivering uncontrollably.
• No alcohol, drugs or medication that makes you drowsy before or during the plunge.