Sauna safety tips: before, during and after every session
Drink first. Keep each round short. Cool down slowly.
A safe sauna session follows a simple rhythm: a glass of water, 5 to 20 minutes in the heat,1 a break, another drink and a slow cool-down. Alcohol waits until afterwards, and no single stay goes past 30 minutes.2 In the picture, the coral line is the heat, the blue line is the water in your body, and each glass tops it back up.
Your sauna session in five stages
Each stage has its own few habits. Select one to jump straight to it, or read down in order.
Before you heat: check the room and pour a glass
A couple of minutes of checking before the heater goes on keeps the rest of the evening relaxed.
The room and the heater
Nothing should sit on or near the heater. Towels, bathing suits, wooden buckets and dippers all stay clear of it,2 and laundry is never dried in the sauna.3 Your heater manual lists the safety distances for your model, so it is worth a read before the first session.4 If you have a fever or feel ill, the sauna can wait for another day.5
You and your drink
Drink a glass of water before you go in, because you will sweat a lot.5 Leave alcohol for another evening: with heat it lowers blood pressure and can cause heart rhythm problems,6 and heater manuals ask you to avoid alcohol, drugs and medication.7 If you have a heart condition, uncontrolled high blood pressure or have recently had a heart attack, talk to your doctor before you start.1
In the heat: how hot, how long and how much steam
How hot
Heater manuals suggest about 65 to 80°C for the room.2 Research reviews describe 80 to 100°C at head height, so the top bench is the hottest seat and a lower bench gives a gentler heat.15 Sit or lie on a towel,2 and leave straight away if you feel weak or unwell.5 Your heart rate can climb to around 120 to 150 beats a minute in the heat,1 which is another reason to keep rounds short.
How much steam
Throw water on the stones with a ladle, a little at a time, and keep your face back from the heater, because the steam leaves it with real force.9 Use clean tap water only: spa, pool or salt water damages the heater.82 Steam makes you sweat harder, which is why the glass of water comes next.
Children in the sauna
Children can enjoy a sauna with a few changes. Keep the room nearer 60°C, stay on the lower benches, limit the time to a few minutes with plenty of cool-down breaks, and keep an adult with them throughout.10 Keep children away from the hot heater.2
PortaSauna HEX 4 Person Portable Outdoor Sauna£1,860
A portable tent sauna that seats up to four, with a traditional wood-fired stove that reaches up to 100°C in 20 to 30 minutes and sets up in about 10 minutes. Water poured over the stones makes real steam, so the ladle-a-little-at-a-time habit in this guide applies from your first session.
Between rounds: step out, cool off and drink
The break is part of the session, not time off from it.
Cooling
Step out when the heat feels like enough. Sit or walk slowly in the fresh air before you rinse off,6 or take a cool shower.5 If you are new to saunas, build up to cold water gradually rather than plunging straight in.6
Drinking
Sip fresh water during the break to replace what you have sweated out.6 Blood pressure dips after a sauna,1 so stand up slowly. Go back in when you feel ready, and stop whenever you feel you have had enough.
Cool-down: a long cool shower, then time to settle
Round the session off with a long, cool shower.8
Letting your body settle
Give yourself a few quiet minutes before you get dressed. Dressing straight away only makes you perspire again, and waiting lets your body cool down fully.8 Keep cooling your skin as often as you need to.2
Topping up
Have a drink of fresh water to bring your fluid balance back to normal.2 Thirst, a headache, feeling dizzy or tired and dark yellow, strong-smelling pee are signs you need more fluid, while pale pee means you are well hydrated.11 Water or diluted squash does the job, and alcohol and caffeinated drinks work against it.11
After the session: dry out, wipe down and check the heater
A few minutes of care keeps the room fresh and the heater safe for next time.
The room
Empty any buckets after every session and keep the air moving so the timber dries.2 Scrub the benches with a soft brush and soapy water or a mild disinfectant when they need it.2 Check that nothing is left on or near the heater, and keep laundry out of the room.3
The heater and stones
Once the stones have cooled completely, take them out now and then and check them for breakages or discolouration, which keeps air flowing round the heating elements.4 Stones that have crumbled or turned to powder, often after one to two years of use, are ready for replacing.2
2 Person Indoor Infrared Sauna£1,199
An indoor infrared cabin with an interior panel for temperature and session length, easy-to-clean wipe-down surfaces and a standard plug. Follow your manual for session times, and the same drink-before-and-after habits apply. See all our saunas or the infrared saunas.
Quick answers
Open a question to read the answer.
How long should you stay in a sauna?
Most people stay for 5 to 20 minutes per round. Heater manufacturers set 30 minutes as the most in one stay, and you can leave sooner whenever you feel weak or unwell. Cool down and drink water between rounds.
Should you drink water before a sauna?
Yes. You sweat a lot in the heat, so a glass of water before you go in helps, and so does sipping water in the breaks and having another drink afterwards.
Can you drink alcohol in a sauna?
No. Alcohol and heat together can lower blood pressure and raise the risk of heart rhythm problems, and sauna heater manuals ask you to avoid alcohol and drugs. Keep it for after you have cooled down and had plenty of water.
How hot should a sauna be?
Heater manuals suggest about 65 to 80°C for the room. The top bench is the hottest seat, so sit lower down if you would like a gentler heat.
What should you do after a sauna?
Take a long cool shower, give your body a few quiet minutes to settle before you get dressed, and drink fresh water. Then empty any buckets, let the room air and check that nothing is left on or near the heater.
Is a sauna safe with a heart condition or high blood pressure?
Talk to your doctor first. The research lists unstable angina, a recent heart attack, uncontrolled high blood pressure, heart failure and severe aortic stenosis as conditions where a doctor's advice comes first, and your doctor can tell you what suits you.
Can children use a sauna?
Yes, with changes. Keep the room nearer 60°C, stay on the lower benches, limit time to a few minutes with plenty of cool-down breaks, keep children away from the heater and have an adult with them throughout.
Sources
- Laukkanen JA, Laukkanen T, Kunutsor SK, Cardiovascular and other health benefits of sauna bathing: a review of the evidence, Mayo Clinic Proceedings, 2018
- Harvia, Owner’s and operator’s manual for sauna heaters K10G-U1 to K15G-U3W, version 27102021
- Harvia support, Quick heater instructions for models with mechanical controls, 25 June 2026
- Harvia, Sustainable sauna experiences: how to ensure safety in saunas
- InfoFinland (KEHA Centre), Finnish sauna, 11 April 2025
- HUUM, How to use a sauna safely, 17 September 2025, updated 6 May 2026
- Sentiotec, Sauna control unit Pro B3, installation and operating manual, version 01/21
- Tylö, Simplified instruction manual, Tylö Deluxe 7, 8 and 11 with TS-30 control
- Finnish Sauna Society, Sauna bathing, sauna rules approved 15 April 2020
- Harvia, Enjoying sauna as a family: sauna tips for families with children
- NHS, Dehydration, last reviewed 1 May 2026
Paul Margerison
Managing Director & Founder, Outdoor Living
A sauna is there to be enjoyed, and a steady rhythm of heat, water and rest is what makes it feel so good. This guide gives you that rhythm from the first drink to the last wipe-down.