If you’re just getting into sauna bathing, you may be feeling overwhelmed with mixed messages. It seems like every other gym, health coach, or podcaster has something different to say about how to best use a sauna and when to do so.
So today, we’ll look at the research, specifically in relation to saunas and sleep. We’ll talk about the impact saunas can have on sleep quality and their other health benefits, as well as when and how to use the sauna to improve your sleep. Saunas are generally considered safe, but they can be more dangerous for certain at-risk people, so we’ll also give you a list of those who should avoid saunas.
Ultimately, we hope you come away with a little less confusion and a lot more confidence about how and when, exactly, to use the sauna to improve your sleep and overall health, according to the research.
How Does Using a Sauna Improve Sleep?
In order to understand how the sauna can help improve sleep, let’s talk about melatonin. Melatonin is a hormone that the body naturally produces when it becomes dark outside1, and it makes us sleepy. This is why it is so important to sleep in a room that is dark; any light let into your room2 could negatively impact your melatonin production.
However, melatonin’s production is not only affected by light; it is also affected by temperature.1 The cooler your body feels at night, the more melatonin you will produce.1 Have you ever tossed and turned because you felt too hot at night? This is likely not just discomfort; it is also because you’re unable to produce as much of the sleepy hormone melatonin when you’re hot.1
This is where saunas come in.
As you probably know, sauna bathing is a form of heat therapy, in which you sit in a small room that can heat up between 158 and 212 degrees Fahrenheit3. The sauna raises your core body temperature while you are in it, but then afterward, your core temperature drops4. This sort of drop in core temperature is one of those things that signals to your body, “It’s time to produce melatonin and go to bed.”
In this way, it is much like taking a warm bath before bed5; both of these forms of “heat therapy” initially raise your core temperature, but then afterward, lower it, which should help the body with its melatonin production.
In addition to triggering this biological mechanism, spending some time in the warm sauna should also help you relax and wind down before bed.3
In fact, in 2019 researchers in Australia conducted a global survey6 of sauna bathers. Of the 482 participants, 83.5 percent reported improved sleep after using the sauna.
Sauna Health Benefits
Aside from improving sleep, regularly using the sauna has been shown to have other health benefits.
First of all, using a sauna can reduce the following health risks7:
- High blood pressure
- Cardiovascular disease
- Neurocognitive diseases
- Pulmonary diseases
Sauna bathing can also have the following positive effects:
- Improve hormonal function8
- Treat symptoms of colds and viruses8
- Help detox the body and (temporarily) help you lose (water) weight8
- Lower bad cholesterol3
- Reduce stress levels3
- Increase circulation3
Of course, much of this can be said of simply doing a moderate amount of exercise each day, and experts at UCLA Health recommend a combination of regular exercise and sauna bathing for the best health results.3
Tips for Using a Sauna Before Bed
The important thing to note here is that timing is key when it comes to using the sauna before bed – use it too early and you won’t get the benefits of a lowered core temperature; use it too late, and you’ll still be hot and either dehydrated or full of water, which will make it harder to sleep.
Related: Learn How to Use a Sauna
In an earlier study, researchers looked at the effects of nighttime sauna bathing on sleep9. They found that the participants’ body temperature rose dramatically while in the sauna. Soon after they got out, their temperature slowly decreased and after about two hours, the participants began getting sleepy.9
This holds up with more modern studies, not on saunas specifically, but on taking a hot bath or shower before bed. In 2019, researchers discovered that a hot bath or shower one to two hours before bed would help induce sleepiness.5
This is because these forms of heat therapy can feel relaxing and help lower the core body temperature afterward, which facilitates melatonin production.
Therefore, it seems the ideal time before bed to use a sauna (or take a hot bath), is about two hours before bed.5,9
One thing to keep in mind, though, is hydration. Normally when you get into the sauna, you stay in long enough to work up a sweat. Most people lose about a pint of sweat10 during a short sit in the sauna. For this reason, it is recommended that you drink two to four glasses of cool water after the sauna, to rehydrate.1.
Unfortunately, two to four glasses of water close to bedtime might mean several trips to the bathroom throughout the night, which is not good for sleep either. Conversely, if you choose to sweat it out in the sauna and then don’t drink enough water afterward, you could experience muscle cramps through the night11.
It seems the solution may be doing a shorter sit in the sauna at night than you might during the day. Sitting long enough that you feel hot, but not so long that you’re pouring out sweat, means you’ll get the benefit of raising and then lowering your core temperature, without losing hydration. In general, though, you should avoid staying in a sauna for more than 20 minutes.10
With regards to hydration, we advise being plenty hydrated before you go into the sauna and then having a little bit of water afterward, but experts recommend12 less than one full glass of water in the two hours before bedtime to avoid waking throughout the night to urinate.
Who Should Not Use a Sauna?
Sitting in the sauna is safe for most people, but certain groups should avoid using one. This includes those who are pregnant13, people with either high or low blood pressure, people currently using nicotine patches, children, those with heart disease, or anyone who is currently ill.8,10
Even if you are not in an at-risk group, you should never get into a sauna if you’ve been drinking, using any stimulants (like cocaine, steroids, etc.), or taking any medications that could decrease your ability to sweat.8
Using The Sauna Before Bed FAQs
Is it good to use a sauna before bed?
Yes, it’s good to use the sauna before bed, but you need to time it right. Using the sauna about two hours before you go to bed should help make you sleepier at bedtime.5,9 At night, sit in the sauna long enough to raise your body temperature, but not long enough to sweat a lot, as both dehydration and drinking a lot of water before bedtime could interfere with sleep.
Is it better to go to the sauna at night or during the day?
You can use the sauna either during the day or at night, depending on what works best for you. At night, using the sauna two hours before bedtime may help you sleep better.5,9
However, experts also recommend using the sauna directly after your workout for maximum health benefits.3 This also tends to work well for many people since the sauna is often located at the gym. So, if you work out in the morning or afternoon, feel free to use the sauna then.
When should you not use a sauna?
Avoid using the sauna in the 30 minutes before bedtime, as your body temperature will likely still be high when you’re ready to go to sleep.4 This can negatively impact your ability to fall asleep.
You should also avoid using the sauna if you have been drinking, are on any stimulants, are using nicotine patches, are on any medications that reduce your ability to sweat, or are currently ill.8 Additionally, you should avoid using the sauna if you are pregnant.13
What are the benefits of going to the sauna every night?
Regularly sitting in the sauna about two hours before bedtime can improve your ability to fall asleep and stay asleep.5,9 Some experts recommend hitting the sauna only two or three times a week.4 Therefore, if you plan on using the sauna every night, make sure you are staying hydrated to replace all the fluid you’re losing.
You might also want to scale back your time in the sauna at night so that you’re just getting hot but not sweating a lot. This way you won’t become dehydrated or have to drink a lot of water before bedtime.
Natalie is a content writer for Sleep Advisor with a deep passion for all things health and a fascination with the mysterious activity that is sleep. Outside of writing about sleep, she is a bestselling author, improviser, and creative writing teacher based out of Austin.
- Xu, Xiaoying., Liu, Xiaoyan., et. al. “Association of Melatonin Production with Seasonal Changes, Low Temperature, and Immuno-Responses in Hamsters”. National Library of Medicine. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6017911/. 2018.
- Marshall, Lisa. “Even minor exposure to light before bedtime may disrupt a preschooler’s sleep”. Colorado University. https://www.colorado.edu/today/2022/01/25/even-minor-exposure-light-bedtime-may-disrupt-preschoolers-sleep. 2022.
- “Benefits of sauna bathing for heart health”. UCLA Health. https://www.uclahealth.org/news/benefits-sauna-bathing-heart-health. 2023.
- DeBara, Deanna. “Sauna & Sleep: A Winning Combo?”. OURA Ring. https://ouraring.com/blog/sauna-sleep-a-winning-combo/. 2023.
- Neilson, Susie. “A Warm Bedtime Bath Can Help You Cool Down And Sleep Better”. National Library of Medicine. https://www.ncbi.nlm.nih.gov/search/research-news/3495/. 2019.
- Hussain, Joy N., Greaves, Ronda F., Cohen, Marc M. “A hot topic for health: Results of the Global Sauna Survey”. ScienceDirect. https://www.sciencedirect.com/science/article/abs/pii/S0965229919300998. 2019.
- Laukkanen MD, Jari A., Laukkanen, Tanjaniina., Kunutsor MD, Setor K. “Cardiovascular and Other Health Benefits of Sauna Bathing: A Review of the Evidence”. Mayo Clinic. https://www.mayoclinicproceedings.org/article/S0025-6196(18)30275-1/fulltext. 2018.
- “Are Saunas Good for You?”. Poison Control. Webpage accessed October 10, 2023. https://www.poison.org/articles/are-saunas-good-for-you.
- Vihavainen, Raili. “Sauna and sleep”. The Finnish Sauna Society. Webpage accessed October 10, 2023. https://sauna.fi/en/sauna-knowledge/sauna-and-sleep/.
- “Sauna Health Benefits: Are saunas healthy or harmful?”. Harvard Health. https://www.health.harvard.edu/staying-healthy/saunas-and-your-health. 2020.
- “Leg Cramps”. Cleveland Clinic. Last modified June 5, 2023. https://my.clevelandclinic.org/health/diseases/14170-leg-cramps.
- “Is It Healthy To Drink Water Before Bed?”. Cleveland Clinic. https://health.clevelandclinic.org/drink-water-before-bed/. 2022.
- “Is it safe to use a sauna or jacuzzi if I’m pregnant?”. National Health Service. Last modified December 22, 2022. https://www.nhs.uk/common-health-questions/pregnancy/is-it-safe-to-use-a-sauna-or-jacuzzi-if-i-am-pregnant/.