Your own sauna and cold plunge at home make for a real treat any time of the year. While most garden buildings find less use in winter, saunas still earn their keep and it’s not hard to see why. 

When it’s cold and dark outside, the better that first wave of heat feels. In Finland and Estonia, countries with traditional sauna culture, you’d follow that with a dip in a cold pond or lake. In a British garden it is more likely a plunge tub, a cold shower or even a hosepipe you have been meaning to lag. 

This guide covers how to run a sauna and cold plunge at home through the winter months: how hot, how long, what to plunge into, and how to keep the sauna itself in good shape until spring.

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Sauna and cold plunge: what is contrast therapy?

Contrast therapy means moving between heat and cold on purpose, usually several times in one session. A sauna and cold plunge is the most familiar version: you heat up properly, cool down quickly, rest, and repeat.

It sounds like a wellness trend, and in all fairness – it is now sold as one. In the Nordic countries and the Baltics it is simply what you do on a Saturday evening, and has been so for countless generations.

Why winter is one of the best times to use your sauna

Winter is when a garden sauna earns its place. On a cold night the contrast is sharper, the cool-down takes care of itself, and there is something quietly satisfying about sitting at 80°C while the frost settles on the lawn outside.

There is a practical side too. Long dark evenings leave fewer reasons to be outdoors, and a sauna gives you one. A 20-metre walk down the garden in a dressing gown is not much of a commute, but it does feel like going somewhere.

How long does a sauna take to heat up in winter?

The Tylö Sense Sport 6 and 8 heaters Summerhouse24 supplies take around 25-45 minutes to reach temperature. In winter, expect the longer end of that range, and a little more on a hard frost. The cold air, walls and stones all have to warm up together, so allow more time than you would in July.

• Electric heaters are the easier option on a weeknight. Many can be set on a timer, so the sauna is warm by the time you have finished dinner.
• Wood-fired stoves take a little longer and need attention while they get going, but give a softer, more traditional heat. Keep your logs under cover – damp wood smokes, spits and heats badly.

If you are still deciding between the two, our guide to electric or wood-fired saunas sets out the running costs and trade-offs side by side.

How hot should a sauna be?

A traditional Finnish-style sauna usually runs at 70–90°C. If you are new to it, 60–70°C is a comfortable place to start. Temperature is not a competition, and the hottest bench is not automatically the best one.

Humidity matters as much as the number on the thermometer. Ladling water onto the hot stones releases a burst of steam, called löyly in Finnish and leil in Estonian, which makes the air feel far hotter for a minute or two. A few ladles per round is enough.

How long should you stay in a sauna?

Most people find 10–15 minutes per round about right, and beginners may want to start at 5–8. The better guide is your own body: leave when you feel properly warm through, not when you feel light-headed or uncomfortable.

A typical home session is two or three rounds of sauna and cold, with a few minutes’ rest between each. That adds up to about an hour, including heat-up time you can spend doing something else.

Your cold plunge options at home

You don’t need a lake or a pond to do your cold plunge after sauna. But if you do have access to a natural body of water, by all means, take advantage of it!

All you really need is cold water, any way you can access it.

A dedicated plunge tub. Purpose-made cold tubs range from simple insulated barrels to chilled, filtered units. In a British winter, an unpowered tub filled from the hose will often sit at 5–10°C without any help. Fit a lid to keep leaves and frost out.

A cold shower. The simplest version, and easier to control. An outdoor shower beside the sauna works well, though the pipework needs insulating or draining down before the first hard frost. If your sauna has a shower room, it’s a convenient option.

Is a cold shower after the sauna as good as a plunge?

A cold shower after the sauna cools you more gently than a full plunge, because only part of your body is in cold water at once. That makes it a sensible way to start. Many people never move beyond it and are quite happy.

A bucket of water. The Estonian countryside method. Fill it before you go in, tip it over your head when you come out. Low-tech, and alarmingly effective.

Snow. Rolling in fresh snow or rubbing it on your body is traditional in the Nordic countries. In most of the UK you will get the chance about once every few years, so make the most of it when it comes.

Choosing a sauna with room for a plunge

If you are planning a sauna with cold plunging in mind, a terrace or partially covered veranda makes winter sessions much easier. It gives you a dry, level spot for a plunge tub or bucket right by the door. You also get somewhere sheltered to cool down between rounds, and you don’t have to cross frozen paving in bare feet.

Here are three sauna models that have a veranda included:

From left to right:

• Oliver II – a 6x2m sauna cabin with a terrace and three rooms, including a changing space.
• Geira – a modern 5x2m thermowood sauna with a partially covered veranda.
• Nord – a modern 5x2m thermowood sauna with a partially covered veranda and a flat roof.

Whichever you choose, measure the covered area against the plunge tub you have in mind before you order. If you prefer one of our other sauna models, but would like a canopy or terrace added, you can request a bespoke design.

How to do a sauna and cold plunge session

Sauna first, then cold – that is the order for almost everyone. A simple routine for a winter evening:

1. Shower and dry off before your first round, so you warm up faster.
2. Sit in the sauna for 10–15 minutes, adding steam once or twice.
3. Step out and cool down: 1–3 minutes in the plunge, or 30 seconds to 2 minutes under a cold shower.
4. Rest for 5–10 minutes. Wrap up, sit down, and drink some water.
5. Repeat for two or three rounds in total.

Some people like to finish on cold. Danish researcher Susanna Søberg, who has studied cold and heat exposure, suggests ending with cold so your body has to rewarm itself. Others prefer a final warm round before bed. Try both and see which suits you.

What are the benefits of a sauna and cold plunge?

The benefits most people notice are simple ones: feeling relaxed, sleeping well afterwards, and feeling warm for hours on a cold evening. Many also describe the cold as an instant reset, which is hard to argue with when you are standing in a tub of 8°C water.

Research, much of it from Finland, has linked regular sauna use with better heart and circulation health. Most of those studies are observational, though, and the evidence on cold plunging is thinner. The honest summary is that a sauna and cold plunge routine is good for winding down, and may do more – but it is not a cure for anything.

Staying safe in the cold

Cold water is the part to respect. The first minute brings a sharp gasp and fast breathing, known as cold water shock. Lower yourself in slowly, keep your head above water, and focus on slowing your breath before you do anything else.

• Build up gradually: start with a cold shower or a short dip, and increase over weeks rather than days.
• Never plunge alone when you are starting out.
• Avoid alcohol before and during a session.
• Drink water between rounds.
• If you have a heart condition, high or low blood pressure, or are pregnant, check with your GP before using a sauna or cold water.
• Never use a frozen pond or open water at home as a plunge.

Looking after your sauna through the winter

A well-built sauna copes with winter without much fuss, but a few habits help it stay dry and sound until spring.

Dry it out after every use. Leave the door and vents open once you are done, so moisture escapes rather than settling into the timber. Avoid placing objects in front of the vents or openings intended for air exchange. Your chosen sauna will have instructions on how to handle maintenance.

Clear heavy snow and leaves from the roof. Barrel saunas shed snow well thanks to their curve. Flatter roofs may need a soft brush after a heavy fall. Make sure to also brush away any snow or leaves blocking vent openings.

Protect the water supply. Drain or lag outdoor taps and shower pipework before the first frost.

Keep the path lit and gritted. Wet bare feet and frozen paving are a bad combination. A few solar or low-voltage lights along the path make winter sessions much more pleasant.

Check the stove or heater. Sweep a wood-burner’s flue before the season starts. For electric heaters, rearrange or replace cracked stones so the air can flow between them.

Plan exterior treatment for spring. Avoid treating the outside in freezing or damp weather. A dry spell in spring is the time for it.

Frequently asked questions

Planning a sauna for next winter?

If this guide has you looking at the corner of your garden, now is a good time to start. Ordering over the winter means your sauna can be installed in spring and ready long before the evenings draw in again. If cold plunging is part of the plan, look at the models with a terrace or veranda, which leave room for a tub right by the door. Browse our garden sauna cabins and outdoor saunas, or get in touch if you would like help choosing.