Sauna and Cold Plunge at Home: How to Do It and How to Set It Up

9 min read

Inside a barrel sauna, looking out through an arched window across a snowy field

Heat, then cold, then rest. Repeat two or three times. That is the whole idea behind sauna and cold plunge, sometimes called contrast therapy, and it has grown fast in recent years. Public sauna and plunge sites keep opening, and more people now want the same routine in their own garden.

This guide explains how a session works, how hot and how cold to go, what the research does and does not show, and how to set up a sauna and cold plunge at home.

What is sauna and cold plunge?

You warm up properly in a sauna, then cool down quickly in cold water, then rest before going again. Each heat, cold and rest cycle is a round.

The heat raises your heart rate and opens blood vessels near the skin. The cold does the opposite, narrowing those vessels and setting off a fast, sharp breathing response. Most people describe the feeling afterwards as calm, warm and very awake at the same time, which is a large part of the appeal.

You will also see it called hot and cold therapy or contrast therapy. In Finland it is simply how a sauna is done: a sauna, then a lake, a snow roll or a cold shower.

Sauna or ice bath: what each does on its own

The sauna. A traditional sauna heats the air to around 158 to 194°F. Your heart rate rises, you sweat and your muscles relax. The best known research comes from Finland, where a 20 year study of 2,315 middle-aged men linked 4 to 7 sauna sessions a week with a lower risk of fatal heart disease than one session a week. That study shows an association, not proof that the sauna caused it. Our page on the benefits of sauna covers the research in more detail.

The cold plunge. Water below 59°F counts as cold. Getting in sets off cold shock: a gasp, fast breathing and a jump in heart rate and blood pressure. That passes within a minute or so, and what follows is the alert, clear-headed feeling people talk about. Athletes use cold water to reduce muscle soreness after hard sessions.

One claim worth dropping: cold water does not “flush out lactic acid”. Lactate returns to normal within about an hour of exercise whatever you do, and it is not what causes next-day soreness.

Together. The research on combining the two is young. The study most often quoted followed a small group of experienced Danish winter swimmers, all young men, who averaged about 11 minutes in cold water and 57 minutes in sauna heat a week. They handled cold differently from non-swimmers, but the study cannot say whether the routine caused that. Treat the specific numbers you see online with care. Treat the routine itself as something many people find genuinely good for how they feel.

A simple sauna and cold plunge routine

There is no official guideline for beginners, so start gently and build up over several weeks. These are sensible starting points, not targets.

SaunaCold plungeRestRounds
First few sessions8 to 10 minutes30 seconds to 1 minute at 54 to 59°F5 to 10 minutes2
Getting used to it10 to 15 minutes1 to 2 minutes at 50 to 59°F5 to 10 minutes2 to 3
Regular12 to 15 minutesup to 3 minutes at 50 to 59°F10 minutes3

These times are for a traditional sauna. In an infrared sauna, which runs at a gentler 113 to 140°F, double the heat time.

Get out of the cold straight away if you feel dizzy, numb or unwell. For context, the experienced winter swimmers in that Danish study averaged under a minute and a half per dip. More is not better.

How to do a round

  1. Heat up. Sit in the sauna until you are properly warm and sweating. Our sauna temperature guide and the post on how long to spend in a sauna help you find your level.
  2. Rinse. A quick shower before the plunge keeps the water clean.
  3. Get in slowly. Lower yourself in rather than jumping. Keep your head above the water and slow your breathing down before you settle. The gasp and fast breathing ease within about a minute.
  4. Get out and rest. Wrap up, sit down and let your body warm back up naturally for 5 to 10 minutes. Drink some water.
  5. Repeat.

Which order, and what to finish on

Start with heat. Going into cold water from cold is harder and less pleasant.

Finishing is personal. Many people like to finish cold for a sharp, awake feeling. Others finish with a final round of heat, especially in the evening before bed. You will often read that you should always end on cold, but there is no strong evidence either way.

How cold should a cold plunge be?

Anything below 59°F does the job. Most home plunges sit between 50 and 59°F, and there is no need to go colder while you are learning.

In the UK, for example, tap water averages around 50 to 59°F across the year. It is colder in winter and warmer in summer, and it varies by region elsewhere. A tub filled from the tap is cold enough for much of the year, but in summer you will need ice or a chiller to get below 59°F.

A tub with a built-in chiller holds the temperature you choose all year round. Chill Tubs, our sister brand within Superior Wellness, makes ice baths with built-in chillers.

Setting up a sauna and cold plunge at home

The best setups keep the walk between heat and cold short, safe and private.

Put them close together. A few steps from the sauna door to the plunge is ideal. You want to step out, rinse and get in while you are still hot.

Make the path safe in winter. Wet feet, frost and decking are a bad combination. Use a non-slip surface, add low lighting and keep the route clear.

Think about water. You will spill water every time you get out, and you will need to empty and refill an unchilled tub regularly. Site the plunge where water can drain away from the sauna base and from the house, and keep a hose or outside tap within reach.

Add a shower if you can. An outdoor shower lets you rinse before the plunge, and on its own it is a good first step if you are not ready for a full tub.

Plan the electrics together. A traditional sauna heater needs its own circuit, fitted and certified by a registered electrician. A chiller needs a properly protected outdoor outlet. If you are planning both, ask the electrician to do the work in one visit. Our garden sauna guide covers bases, power and planning rules in full.

Cover the tub. A lid keeps leaves and rain out, holds the temperature and stops anyone falling in. In a hard frost, an uncovered tub without a chiller can ice over.

Keep it private. Half the session happens outside the sauna. A fence, hedge or screen around the plunge and the rest area makes the whole routine more relaxing.

Which Hekla sauna pairs best with a cold plunge?

Any of our outdoor saunas works well beside a plunge tub. A few things to weigh up:

  • Barrel saunas are the classic choice for this kind of routine. Both take a Harvia electric heater or a Harvia Linear 18 wood-burning stove, if you want a real fire for the heat half of the session.
  • Cube saunas have a full glass front, so you can see the garden, and the plunge, from the bench.
  • Size. For one or two people, a 2 person sauna heats faster and costs less to run between plunges. For a household or friends taking turns in the tub, look at 3 to 4 person saunas.

An electric Harvia heater is usually ready in 30 to 45 minutes, so you can start it from the house and fill or check the tub while it heats. If you have room indoors instead, a traditional sauna works just as well with a cold shower or a plunge tub on a patio. Our guide to what it costs to run a sauna helps you budget for regular sessions.

To see the range in person and talk through a setup, find your nearest Hekla stockist.

Is sauna and cold plunge safe?

For most healthy adults, yes, if you build up gradually and listen to your body. Both heat and cold put real stress on the heart and circulation, so a few rules matter.

  • Check with your doctor first if you have a heart condition, high or low blood pressure, Raynaud’s, or are pregnant. The British Heart Foundation notes that cold shock raises heart rate and blood pressure.
  • Never after alcohol. Drinking in or around the sauna raises the risk of fainting and heart rhythm problems.
  • Never alone in the cold. Have someone nearby, especially while you are learning.
  • Get in slowly and keep your head above the water.
  • Stop if you feel dizzy, numb or unwell, and warm up gently afterwards.

Our post on when it’s best to skip the sauna covers the times to give it a miss.

Sauna and cold plunge FAQs

Start with 30 seconds to a minute and build up to 2 or 3 minutes at most. Experienced winter swimmers in one Danish study averaged under a minute and a half per dip.

Two rounds is plenty to start with. Most regular users settle on two or three.

Yes, as a starting point. A cold shower is less intense than full immersion, but it gives you the same heat then cold rhythm and is the traditional Finnish fallback when there is no lake.

It depends on your goal. Cold water can ease soreness, but if you lift weights to build muscle, wait a while before plunging. In one 12 week study, men who took a 10 minute cold bath after strength training gained less muscle and strength than men who did an active cool-down instead. Our post on sauna before and after workouts has more.

Either. Finish cold if you want to feel alert, or warm if you are heading to bed. There is no strong evidence that one is better.

Many people say a session in the evening helps them switch off, and a warm finish followed by cooling down naturally can make you feel ready for bed. There is not yet good research on the combination and sleep.

Sources

Read next

Find your sauna with Hekla

Explore Hekla saunas Visit the sauna blog