Cold Plunging in Winter: Do You Need a Chiller and How to Keep It From Freezing

Cold plunging doesn't have to stop when the temperature drops. In fact, many people find that winter is when an outdoor cold plunge feels the most natural, especially when it's paired with a warm sauna.

But winter also brings new questions. If the air outside is already freezing, do you still need a chiller? What happens to your plunge when temperatures drop below 32°F? And how do you keep the water from turning into a block of ice?

The good news is that you can enjoy a cold plunge in winter with the right setup and a few simple habits.

Here's what you need to know about chillers, freeze protection, and staying safe in cold weather.

Yes, you can cold plunge outdoors in winter, as long as your plunge is designed for outdoor use and set up correctly.

Winter adds a few challenges that you don't face in summer. Water can get colder than you expect, equipment can freeze, and paths can turn icy.

Before you start, make sure you have:

• An outdoor-rated plunge: Check that your tub, chiller, and cover are approved for outdoor use.
• A safe electrical setup: Chillers and pumps should be installed according to their manuals and local electrical codes.
• A freeze protection plan: Know how you'll keep the water and equipment from freezing between sessions.
• Safe access: Keep the area around your plunge clear of snow and ice.
  

Always follow the manufacturer's instructions for your specific plunge and chiller.

You don't always need a chiller to make the water cold in winter. But a chiller is still one of the most useful tools for winter plunging, because it helps you control the water temperature, not just lower it.

In many climates, winter air can cool an outdoor plunge below the range most people use. Cleveland Clinic suggests that beginners start at 50–59°F and avoid water
colder than 40°F (Cleveland Clinic). Without temperature control, your water may end up colder than you want, or start to freeze.

A plunge without a chiller can work in winter if:

• You plunge indoors in a space that stays above freezing.
• Your winters are mild, and outdoor temperatures rarely drop below freezing.
• You use your plunge seasonally and drain it before the coldest months.
• You're comfortable checking the water with a thermometer before every session.

If you'd rather start simple, a standalone tub like those in our ice bath collection can be a good first step.

A chiller does more than cool water. For year-round use, it can help with:

• Steady temperature: Set your preferred temperature and keep it consistent, whether it's warm or cold outside.
• Heating mode: Many chillers can both cool and heat. In winter, heating mode can help keep the water from getting too cold.
• Circulation and filtration: Chillers move water through a filter, which helps keep it clean.
• No ice runs: You won't need to buy and add ice to reach your target temperature during warmer months.
• Remote monitoring: Some models let you check and adjust the temperature from an app.

Browse our cold plunge chillers, including cold/heat systems designed for year-round use.

An electric sauna heater uses electrical heating elements to warm sauna stones and heat the room. Once installed, it offers a straightforward way to enjoy your outdoor sauna throughout winter.

For homeowners who prefer convenience, electric heating is often the easier option.

If you plan to plunge outdoors year-round, check these features before you buy.

• Cooling and heating: A cold/heat system gives you more control in winter.
• Outdoor rating and operating range: Check the manual for the outdoor temperatures the chiller is designed to run in.
• The right size: Choose a chiller sized for your tub's water volume, based on the manufacturer's specifications.
• Filtration: A built-in or add-on filter helps keep water clean over long periods.
• App control: Wi-Fi models make it easier to check on your plunge without going outside.
• Power needs: Use a dedicated outlet or circuit with GFCI protection where required, and follow the manufacturer's electrical instructions.
  

Water freezes at 32°F, and still water in an outdoor tub can freeze quickly during a cold night. Ice can damage tubs, hoses, pumps, and chillers.

These steps can help protect your plunge all winter.

1. Use an Insulated Cover

An insulated cover helps hold in heat, keeps out snow and debris, and reduces the chance of a frozen surface.

2. Keep the Water Moving

Circulating water is less likely to freeze than still water.

If your chiller or pump has a circulation or freeze-protection setting, keep it running in freezing weather as directed by the manufacturer.

3. Use Your Chiller's Heating Mode

If your chiller can heat, set a minimum water temperature that keeps the water safely above freezing.

Check your manual for the recommended winter settings for your model.

4. Protect Hoses and Exposed Parts

Hoses, fittings, and pumps usually freeze before the tub does.

Keep hoses as short as the setup allows, protect exposed lines as recommended by the manufacturer, and keep snow from piling up on the chiller. Never block the chiller's air vents, since it needs airflow to run properly.

5. Plan for Power Outages

A winter storm can shut off your chiller and pump, leaving the water still and unheated.

If the power goes out during freezing weather, follow your manufacturer's instructions for protecting the equipment, which may include draining the hoses or chiller. Inspect everything for damage before you restart it.

6. Winterize If You Won't Use It

If you plan to take a break from plunging during the coldest months, winterizing is often the safest option.

Drain the tub, hoses, and chiller according to the manufacturer's instructions, dry the parts, and store the cover and equipment as recommended.

7. Avoid Unapproved Heaters and De-Icers

Don't use space heaters, heat lamps, salt, or chemical de-icers in or near your plunge unless the manufacturer specifically approves them. They can damage the tub or equipment and create safety hazards.

You don't always need a chiller to get cold water in winter. But if you want to plunge outdoors all season, a chiller with heating mode makes it much easier to keep the water at a steady, comfortable temperature and help protect it from freezing.

If you plunge indoors, live somewhere with mild winters, or only use your plunge seasonally, a simpler setup may be all you need.

Whichever you choose, focus on freeze protection, a safe setup, and short, careful sessions.

Ready to plunge this winter?

Explore our cold plunges, cold plunge chillers, and plunge accessories, or pair your plunge with one of our outdoor saunas.