Getting a good night’s sleep significantly impacts how we feel the next day, which is why so many people are willing to do and pay whatever it takes for quality sleep. Although cold plunges and saunas have long been used for wellness, they have gained even more popularity recently — especially as some swear by them for their stress-relieving properties and sleep benefits.

If you’re interested in trying saunas or cold plunges, it’s important to understand the health benefits and risks before doing so.

Are saunas good for sleep?

Although saunas and sleep have a long history, it’s important to look at the science. According to a meta-analysis of sauna research, time in a sauna is correlated to improved sleep, among other reported benefits. Likewise, a global survey found that respondents are likely to use saunas for sleep and improved mental health; 83.5% said they experienced the benefits of a sauna before bed for sleep.

Many claim that saunas improve their sleep but the exact mechanics behind this still need further research. Being warm and relaxed can help on its own but the extreme conditions of saunas may be doing more than simply warming your muscles. Annie Miller, licensed psychotherapist and sleep expert, told CNET, “Your body’s circadian rhythm, or body clock, lowers your core body temperature starting about two hours before bed to help you prepare for sleep.” The high temperatures of a sauna may be too extreme for some and may interfere with the body’s need to lower its temperature before bed. However, some proponents of saunas believe regular use of these rooms can help boost melatonin production in individuals, although more studies may be needed.

4 possible benefits of saunas for sleep

This ancient health technique might help with quality sleep in a few ways. Some people think that saunas increase melatonin production, a hormone that causes sleepiness and can help people fall asleep and stay asleep. The heart and vascular system are also put through a workout when you spend time in a sauna, and afterward, the return to resting rates may help induce comfortable fatigue. One group of researchers found that saunas could profoundly mitigate stress for those who work in high-stress occupations, highlighting the capacity of a sauna to encourage a relaxed, low-stress state in people.

• May encourage melatonin production: Melatonin is a hormone that helps with falling and staying asleep. More research is needed to further link melatonin production and saunas.
• Relaxes muscles: Relaxed muscles are essential for allowing the body to rest and prepare for sleep.
• Exercises the vascular system: Returning to a normal resting state after an elevated one can help people become drowsy and fall asleep. The activation of the parasympathetic nervous system also promotes relaxation. 
• Reduces physical and mental stress: Falling and staying asleep is generally far easier with lower physical and mental stress. Saunas also provide space away from distractions, stressors and devices that can aid in sleep. 

Are cold plunges good for sleep?

Well-documented research underscores the connections between body temperature, or thermoregulation, and the ease of falling asleep, with becoming colder toward the evening associated with increased sleepiness. While this study doesn’t specifically focus on cold plunges, it identifies the underlying connection that ice baths may depend upon to encourage quality sleep. Stanford researchers found that cold water immersion can reduce cortisol levels, a hormone strongly associated with stress. High cortisol levels are traditionally seen as a barrier to sleep, so lowering these levels and reducing stress can make sleep come easier. Between lowered body temperature and reduced cortisol levels, safely used cold plunges seem likely to help people fall asleep.

4 possible benefits of cold plunges for sleep

Cold plunges and sleep could tie together in a handful of beneficial ways. As previously noted, immersion in cold water can lower body temperature, encouraging a sleepier state of being. Likewise, cold plunges can reduce cortisol levels, which can help put the body in a more relaxed, sleep-prone state. Researchers at the University of Oregon found that the benefits of cold therapy could potentially aid sleep and included reduced heart rate, blood pressure and cortisol. 

“Taking a cold plunge too close to bedtime might actually interfere with sleep due to the initial ‘fight or flight’ response triggered by the cold,” Miller added. “Timing for a cold plunge matters and earlier in the day might be a more effective time.” But don’t expect results immediately. It will most likely happen over time. 

• Reduced cortisol levels: Lower cortisol is associated with lower stress levels, which can help you get closer to a state of sleep.
• Reduced heart rate: Lower heart rates are associated with a more restful state closer to being asleep, while higher heart rates are associated with being more awake and alert.
• Reduced blood pressure: Lower blood pressure, like heart rate, is associated with a more restful state, closer to sleep.
• Lowered body temperature: Body temperature is closely linked to circadian rhythm, with reduced body temperature occurring close to sleep.

Health risks to consider with saunas and cold plunges

Although there are several potential health and sleep benefits, there are also some health risks to consider and some people should avoid saunas or cold plunges altogether. For instance, saunas should be avoided by people experiencing complicated pregnancies, unstable angina pectoris, recent myocardial infarction or severe aortic stenosis. People should avoid cold plunges if they have heart disease, high blood pressure, diabetes, poor circulation, Raynaud’s phenomenon, peripheral vascular disease, impaired sensation or a pacemaker. Before deciding if a sauna or cold plunge is right for you, speak to your medical professional to ensure you aren’t at risk.

Beyond conditions that should encourage one to avoid these ancient remedies, there are a few health risks to be aware of with cold plunges and saunas. Cold plunges must be carefully regulated, as submersion in water of less than 60 degrees can be lethal in less than a minute. If you experience chest pain, difficulty breathing, dizziness or a change in color, you should immediately remove yourself from the cold plunge and consider contacting a medical professional if the symptoms persist.

With saunas, one of the main risks is extreme dehydration or experiencing arrhythmias if you have been drinking before using the sauna. To mitigate these risks, stay well hydrated and avoid using the sauna if you’ve been drinking alcohol or using other intoxicating substances. 

The information contained in this article is for educational and informational purposes only and is not intended as health or medical advice. Always consult a physician or other qualified health provider regarding any questions you may have about a medical condition or health objectives.