13 Ways to Keep an Ice Bath from Freezing in the Winter

In the cold winter months, maintaining an ice bath can become a challenging task.

The propensity for water to freeze over can significantly impede the benefits and accessibility of ice baths, commonly used for recovery and health benefits.

Here is a quick summary of the best ways to keep an ice bath from Freezing in the winter:

Keep an outdoor ice bath from freezing in winter by insulating the top and sides with a fitted cover, sheltering the tub from wind, insulating it from the ground, and, where the maker allows it, running a circulation or heating system built for cold plunge tubs. Heaters, de-icers and pumps made for livestock tanks, ponds or aquariums are not made for water that people get into. If the tub cannot be kept above freezing, drain it.

This article covers 13 ways to protect an ice bath in freezing weather, and the safety limits of each.

Importance of Preventing Ice Baths from Freezing Over

Preventing your ice bath from freezing over in winter is crucial for several reasons.

First, it ensures that the bath remains ready for use at any time, providing consistent access for those who rely on cold immersion therapy for recovery or health benefits.

A Cochrane review found some evidence that cold water immersion reduces muscle soreness after exercise. Other claimed benefits are less certain, and a cardiologist quoted by the American Heart Association says the wider health benefits have not been established.

However, when an ice bath freezes over, it not only becomes unusable but also requires significant effort and time to restore to a usable state.

Moreover, preventing freezing can help in maintaining the integrity of the bath structure.

Repeated freeze-thaw cycles can cause damage to containers, leading to leaks or structural failure over time.

Water expands as it turns to ice, which is what splits tubs, fittings, pumps and pipes.

By keeping the water from freezing, you extend the lifespan of your ice bath setup, ensuring it remains effective and safe for use throughout the winter months.

13 Ways to Keep Your Ice Bath from Freezing Over

Here are 13 ways to keep an ice bath from freezing in winter, with the limits and safety points of each.

One rule applies to every electrical method below: plug the device into a GFCI-protected outdoor outlet, do not use an extension cord, and keep cords and plug-in products well away from the water. The CPSC says it is aware of 33 electrocution deaths in swimming pools and spas since 2002.

1. Insulation Covers

One effective method to prevent your ice bath from freezing is to use insulation covers.

These covers work by trapping heat within the water and reducing evaporation and heat loss from the water’s surface.

You can find covers made from various materials, including foam and insulated fabric, which are designed to fit snugly over the top of your bath. For optimal results, choose a cover with a high R-value, indicating superior insulation properties.

Additionally, consider covering the sides of the bath as well to minimize heat loss further.

2. Saltwater Solution

Adding salt to your ice bath can lower the freezing point of water. The salty water is called brine.

Salt only lowers the freezing point by a few degrees unless a great deal is used. NOAA notes that seawater freezes at about 28.4°F (-1.9°C), compared with 32°F (0°C) for fresh water.

The amount of salt needed will depend on the size of your bath and the desired freezing point. However, it’s important to note that salt can be corrosive to certain materials and may not be suitable for all types of baths.

Salted water can stay liquid below 32°F (0°C), so it can be colder than any plain ice bath. Do not get into water that is below freezing. Check the tub and chiller instructions before adding salt. Plunge, for example, says damage caused by improper water chemistry is not covered under its warranty.

Always research the compatibility of salt with your bath materials before proceeding.

3. Submersible Heaters and De-Icers (Unattended Tubs Only)

Submersible heaters and stock tank de-icers can keep water from icing over, but they are made for livestock tanks, ponds and aquariums, not for tubs that people get into.

These devices are designed to be placed directly in the water, where they use electrical resistance to heat the surrounding liquid.

Stock tank de-icers are built only to keep water from icing over. They are not designed to hold a chosen bathing temperature.

If a de-icer is used to keep an unattended tub from freezing, follow the maker instructions. Farm Innovators, for example, requires a GFCI outlet, forbids extension cords and says to unplug the unit before removing it from the tank. Unplug it and lift it out before anyone touches or gets into the water, and never get into a tub with a mains-powered heater in it. Aquarium heaters are not suitable. Fluval states that its aquarium heaters are for indoor aquarium use only.

4. Circulation Pumps

Circulation pumps keep water moving, which slows ice formation but does not stop it. Moving fresh water still freezes at 32°F (0°C).

By continuously circulating the water, these pumps distribute heat evenly throughout the bath, reducing cold spots where ice could start to form.

When choosing a circulation pump, look for models that are energy-efficient and have enough power to circulate the volume of your bath effectively.

Use only a pump or chiller that the tub maker supplies or approves, and follow its cold weather limits. Plunge says its tub, filter and chiller must be drained and winterized if the air stays below 32°F (0°C) for 12 hours, and that freeze damage is not covered by its warranty.

5. Solar Water Heaters

Solar water heaters harness the power of the sun to keep your ice bath from freezing.

These systems typically consist of a solar collector connected to a network of pipes that circulate water through the system, warming it before returning it to the bath.

Solar heating gives little or nothing on overcast days and at night. In freezing weather the collector and pipes can themselves freeze, so the US Department of Energy says collector systems used in colder conditions must include freeze protection.

For the best results, combine a solar water heater with another method, such as insulation, to maintain temperature overnight.

6. Wind Barriers

Wind barriers slow the rate at which wind strips heat from the tub and the water surface. The National Weather Service explains that wind chill does not cool an object below the air temperature. It only shortens the time the object takes to cool.

By erecting barriers such as fencing, fabric screens, or natural vegetation, you can shield your bath from direct wind exposure.

The effectiveness of wind barriers will depend on their height, density, and the direction of prevailing winds, so it’s important to design your barrier with these factors in mind.

Also, wind barriers can provide privacy for bath users, enhancing the overall experience.

7. Thermal Ground Mats

Placing thermal ground mats beneath your ice bath can help insulate it from the cold ground.

These mats slow the flow of heat from the water into the ground. Heat moves from warmer to cooler areas, so the aim is to keep the heat in the water.

When selecting ground mats, look for products with high thermal resistance and durability to withstand the weight of the bath and water.

This method is particularly useful for portable baths or those not permanently installed.

8. What Not to Add: Antifreeze

Pool antifreeze should not be added to ice bath water.

Pool antifreeze is made to be poured into drained pool plumbing for the winter, not into water that people bathe in.

Never use automotive antifreeze near a tub. The US Agency for Toxic Substances and Disease Registry says ethylene glycol, which is used to make car antifreeze, can cause serious illness or death if swallowed.

To protect the pump and pipes of an empty tub over winter, follow the winterizing instructions from the tub maker.

9. Electric Heat Mats

Electric heat mats or heat cables placed under or around the tub can add some heat, but only use a product whose maker rates it for outdoor, wet locations and for this kind of use.

These mats are particularly effective when used in conjunction with insulation covers, creating a warm environment that keeps the water temperature above freezing.

When selecting an electric heat mat, it’s important to choose one that is waterproof and designed for outdoor use.

Plug it into a GFCI-protected outlet, keep cords and connections well away from the water, and switch it off and unplug it before using the bath.

You might want to also consider the energy consumption of the mat to ensure it’s a cost-effective solution for your needs.

10. Bubble Covers

Bubble covers, similar to those used in swimming pools, can be adapted for ice baths to reduce heat loss through evaporation and convection.

These covers are made from a lightweight, bubble-wrap-like material that floats on the water’s surface, providing an insulating layer.

The air bubbles in the material trap heat, keeping the water warmer for longer periods.

Bubble covers are easy to install and remove, making them a convenient option for daily use.

For enhanced insulation, combine a bubble cover with other methods, such as an insulated lid or wind barriers.

11. Aerators

Aerators work by injecting air into the water, creating movement that discourages ice formation.

In ponds, aerators keep a patch of water open in the ice by bringing slightly warmer deep water to the surface. A shallow tub has no warmer deep layer to draw on, so the effect is much weaker.

The movement can delay surface ice, but mixing also cools the whole tub toward freezing, so an aerator will not stop a tub freezing in a hard frost.

When choosing an aerator, consider the size of your ice bath and the flow rate of the device to ensure effective coverage.

Aerators are especially useful in regions where temperatures hover around the freezing point, as the movement can be enough to delay ice forming. Keep the air pump out of the water, under cover, and on a GFCI-protected outlet.

12. Insulated Bath Enclosures

Building or purchasing an insulated bath enclosure can provide comprehensive protection from the cold.

These enclosures can be constructed from various materials, such as wood, foam insulation, or even thermal fabrics, and are designed to surround the ice bath, trapping heat inside.

The key is to ensure that the enclosure is well-sealed and insulated to minimize heat escape.

Enclosures also offer privacy. Do not use fuel-burning heaters or lamps inside an enclosure, because of carbon monoxide. Keep any mains-powered heater, lamp or cord well away from the water and on a GFCI-protected outlet.

This solution is ideal for those who use their ice bath frequently and require a durable and long-term solution.

13. Automated Temperature Control Systems

Investing in an automated temperature control system allows for precise regulation of water temperature within the cold weather limits the maker sets.

These systems typically include a thermostat, sensors, and heating elements that work together to monitor and adjust the water temperature.

Choose a system that the tub maker sells or approves for use with people in the water, and check its minimum operating temperature before relying on it through winter.

Automated systems can be programmed to maintain a specific temperature range.

While this option may represent a higher initial investment, it offers convenience, efficiency, and peace of mind, particularly for those who rely on their ice bath for daily therapy or recovery.

This video shows one approach to winterizing an ice bath:

Is it Safe to Take an Ice Bath Outside in the Winter?

Taking an ice bath outside in the winter can be safe, but it requires careful consideration and preparation to avoid health risks such as hypothermia.

Keep sessions short. Mayo Clinic Health System says people typically start with 30 seconds to a minute and work up to five to 10 minutes. The first minute carries the highest risk because of the cold shock response, so get in slowly and never bathe alone.

It’s essential to have a warm environment to retreat to immediately after your session.

Dressing warmly after exiting the bath and drinking warm, non-alcoholic fluids can help raise your body temperature back to normal levels quickly.

Check weather conditions before deciding to take an ice bath outdoors in winter.

Extreme cold and windy conditions can increase the risk of cold-related injuries.

Consulting with a healthcare provider before starting any cold therapy regimen is also recommended, especially for individuals with cardiovascular conditions or sensitivity to cold.

How Do You Fill an Ice Bath in the Winter?

Filling an ice bath in the winter requires a strategy to ensure that the water does not freeze and remains at a manageable temperature for immersion.

First, use warm water to fill the bath. Do not fill with very hot water, which can scald. Hand-test the water before getting in.

This will take longer to cool down to the desired cold temperature, especially in freezing outdoor conditions.

If you’re using an outdoor bath, consider connecting your hose to an indoor tap with access to warm water.

This gives more control over the starting water temperature.

Additionally, covering the bath immediately after filling it can help retain the warmth until you’re ready to use it.

For those in areas where water lines might freeze, storing large containers of water indoors and then transferring them outside for your bath can be an effective approach.

Check the water temperature with a thermometer before each use.

Final Thoughts: Ways to Keep an Ice Bath from Freezing in the Winter

While the weather outside is frightful, your ice bath experience can still be delightful.

Insulation, wind shelter and a maker-approved circulation or heating system do most of the work. Treat any mains-powered device near the tub with care, and drain the tub when it cannot be kept above freezing.

Read This Next:

• What Is a Cold Plunge Tub?
• Why Is Water Cold?

Sources

CPSC (electrical safety around pools and spas)
Plunge (chiller manual)
Farm Innovators (de-icer instructions)
Fluval (aquarium heater manual)
National Weather Service (wind chill)
NOAA (freezing point of seawater)
US Department of Energy (solar pool heaters)
US Department of Energy (pool covers)
ATSDR (ethylene glycol)
Mayo Clinic Health System (cold plunge after workouts)

Reviewed October 2026. We removed claims of testing, changed the advice on submersible heaters, pool antifreeze and electric heat mats using maker manuals and CPSC guidance, corrected the physics of wind chill, salt and aerators using NWS, NOAA and Department of Energy sources, and added electrical and cold water safety points.