Introduction

Did you know we spend about a third of our lives sleeping in bed?¹ That’s why it is a good idea to think about sleep hygiene, including what you wear (or don’t wear) during your sleep. For many of us, slipping into pyjamas is a routine we don’t even think about. Others might even fall asleep in their office clothes or jeans.  However, have you ever considered sleeping naked? Or maybe you've already tried that and want to know if it is good for your health? Sleeping naked is more common than you think, and research suggests it can influence both physical and mental well-being. 

Of course, it’s not the right choice for everyone. In this article, we’ll explore the potential effects of sleeping without clothes, the physiological and psychological benefits, and the situations where it may not be advisable. 

The science of sleep and body temperature

The sleep-wake regulation is based on the circadian rhythms and homeostasis.² Many factors can affect these systems, including health conditions, behaviour, mental health, and environmental influences (such as light, noise, and temperature). Among environmental factors, temperature is one of the most important for ensuring good sleep quality.³  

Sleep timing is linked to the body’s temperature rhythm, which is regulated by skin receptors of warmth and cold. These receptors contribute significantly to thermoregulation by regulating blood flow to the skin and controlling heat loss.⁴

Falling asleep (or sleep onset) typically occurs as the core body temperature begins to decline. To understand the mechanism behind it, it is necessary to separate skin temperature (on the surface) and core body temperature (inside your body, around 36.6–37°C).²

Under normal conditions, the skin is a good insulator – it keeps your body heat in. But once the surrounding environment warms up to about 35°C, the skin stops insulating and lets heat escape much more easily. So even if the temperature difference between your core and the room is small, your body may still lose heat more effectively, because your skin is allowing that heat to flow out. This is due to increased blood flow to the skin’s surface. As a result, raising skin temperature slightly may help cool down your core and support sleep onset.⁴ Skin temperature remains relatively steady during sleep, showing a slight increase during the rapid eye movement (REM) phase.³

How clothing affects thermal regulation

Achieving thermal comfort is important for sleeping well. Although it’s worth mentioning that a stable core body temperature varies from person to person.³ 

If we try to improve sleep by heating the body from the outside by using heated blankets or warm mattresses, it’s important not to warm up the body too much, so that it will prevent the necessary drop in core temperature. 

Studies show that bedding elements, including clothing and mattress choice, impact both thermal comfort and sleep quality.⁵ Sleepwear and bedding create a barrier around the body, impacting skin and core temperature, and therefore significantly affect sleep. To help maintain thermal balance during sleep, clothing acts as a source of insulation and resistance to heat loss. 

The fabric might also be important in terms of insulation and water vapour resistance, like natural fibres (e.g., cotton and wool), which have lower thermal conductivity when dry and increase after moisture absorption.³

To keep thermal comfort under normal or warm conditions, a fibre's water vapour permeability should be high to allow sweat to evaporate from the skin, keeping it dry, like wool.³ 

How can sleeping naked affect sleep?

Sleeping without clothes removes the insulating barrier, allowing the skin to release heat more effectively and helping to lower the body’s core temperature as needed for sleep onset. This, in turn, may lead to deeper and more restful sleep. Additionally, in warmer climates, sleeping naked can help prevent overheating, which is important for better sleep quality.

Potential health benefits of sleeping naked

Better sleep quality

Sleeping naked might induce the cooling effect of the body, helping to fall asleep faster and transition into deeper sleep stages.  Studies indicate that exposure to heat leads to more wakefulness and a reduction in both slow-wave and REM sleep.² Exposure to humid heat increases the sensation of warmth during sleep and can influence both sleep stages and thermoregulation. But a colder environment does not affect sleep stages. However, it is important to define “hot” and “cold”, as it may be different for each individual. 

Studies with healthy volunteers who were exposed to different ambient temperatures to observe metabolic and thermal responses showed that uncomfortable zones for sleep disturbance start from 30°C and higher (too warm), and from 20°C and lower (too cold). The comfortable temperature threshold is considered to be around 25°C, when a person can sleep naked comfortably.⁶ 

Improved skin health

Irritating fabric and the friction from clothes can lead to skin problems, especially for sensitive skin or when the sleepwear fabric is of poor quality.³ This is known as chafing. While it’s not dangerous to your overall health, it can cause unpleasant sensations and visible skin changes. So, letting go of clothes might be a good idea if you're experiencing skin discomfort. Not to mention, it can also improve air circulation in sensitive areas.

Reproductive health 

People assigned male at birth (AMAB)

Exposure to heat and high temperatures can have an impact on male fertility.⁷ Elevated temperatures may impair sperm production (spermatogenesis) and reduce sperm count, motility, and morphology. Wearing loose-fitting pants and underwear is generally considered protective against potential fertility issues. Wearing tight underwear or sleeping in underwear may increase the local temperature in the scrotum, potentially disrupting sperm production.⁸ However, current evidence on the impact of heat on male fertility isn’t strong enough to make this a definitive risk factor.⁹ 

That said, if you're facing challenges in your reproductive journey, it might be worth considering leaving your underwear in the drawer at bedtime.

People assigned female at birth (AFAB)

There is evidence from studies suggesting that wearing underwear may affect your health by increasing the risk of conditions like vulvovaginitis, vaginitis, and yeast infections.¹⁰ Of course, you don’t have to give up underwear entirely, but choosing to sleep without it might be a sensible way to protect your reproductive health.

Mental health and stress reduction

Do you feel better after long office hours when you come home, take off your work clothes, belts, and tight shoes, and slip into some loose cotton or silk home wear? Of course you do. The same applies to nighttime, when you take off your clothes and nothing is tightening or restricting you.

That feeling of comfort and relaxation kicks in, and you might even feel happier as you get ready for bed. A study by Japanese researchers showed that wearing tight clothes can activate the sympathetic nervous system, which is linked to stress.¹¹ 

Another thing to consider is how clothes can get twisted while you move in your sleep. Sometimes they bunch up or wrap around you in a way that restricts movement and may even disrupt your sleep. Sleeping without that interference can feel more freeing and relaxing.

Improving a relationship 

A study from 2015 explored how different behaviours and skin-to-skin contact can increase levels of oxytocin – a hormone linked to stress reduction and intimacy.¹² So, if you have a partner and you're both considering sleeping without clothes, it might be a good idea to strengthen your relationship and lower stress levels. 

Potential drawbacks or considerations

Decreased temperature

There is a risk of getting cold at night, especially if the temperature drops.¹³ In addition, thermoregulation may be compromised in certain groups, such as infants, older adults, or people with chronic conditions or illnesses. These changes in body temperature can lead to sleep disruptions and poorer sleep quality.

However, it doesn’t mean you shouldn’t sleep naked. You can still enjoy its benefits by using layered blankets and breathable sheets.

Hygiene and cleanliness

During sleep, we sweat, and some people may be more prone to sweating, especially in warmer conditions. Pyjamas help absorb this sweat and keep the skin dry, particularly if they’re made from fabrics like viscose or bamboo lyocell, which often have antibacterial properties.³ Without pyjamas, this job falls to your bed sheets, which then absorb sweat, oils, and moisture, potentially leading to bacterial growth and discomfort.

Bed sheets can also collect dust and dirt from the surrounding environment.³ Over time, this buildup can affect your skin and may even trigger allergic reactions with consistent contact. Also, some sheet materials that don’t allow proper evaporation can irritate the skin, especially if it’s sensitive.

That’s why it’s important to wash your sheets regularly, especially if you decide to sleep without pyjamas.

Living situation

There are also some practical, non-health-related factors to consider when deciding whether to sleep naked. For example, if you have children at home or share your living space with people other than your partner, it might be best to avoid sleeping naked – for obvious reasons related to privacy and comfort. Sleepwalkers should also keep that in mind. 

In case of an emergency, e.g., a fire alarm, you need to get up and leave the house quickly. Taking time to get dressed or having to run outside without clothes, especially in cold weather, can be both unsafe and highly uncomfortable. Even in warmer conditions, appearing unclothed in front of your neighbours is not the most pleasant situation at all.  

There might be a solution for potential emergencies, though – keep the pyjamas or loose clothing within easy reach, like under your pillow, so you can put them on quickly if needed.

Who might benefit most?

Sleeping naked might be a good idea if you are:

• Generally healthy and young, without chronic conditions or skin irritations
• Living alone or with a partner, without children or other housemates
• A woman experiencing vulvovaginitis or yeast infections
• A man with fertility issues, especially in hot climates
• Living in a hot area or during a period of high temperatures
• Someone who changes bed sheets regularly (every 1–2 weeks)
• In a couple looking to increase intimacy
• Struggling with falling asleep or experiencing insomnia

Who might want to avoid it?

It is not recommended to sleep naked if you are:

• An older adult
• A newborn or a child
• Pregnant or lactating
• Living with children or in shared spaces
• Prone to excessive sweating
• A sleepwalker

You might consider sleeping naked, but do so with caution or after seeking medical advice, if you: 

• Have chronic health conditions (e.g., heart disease, endocrine or autoimmune disorders)
• Have allergies or sensitive skin conditions
• Don’t change your bed sheets regularly (at least twice a month)
• Often feel cold easily or live in a colder climate

Tips for trying it out

• Start by removing some layers, e.g., your panties or a T-shirt. Or you could try lying naked and covering yourself with a blanket 
• Make sure your bedding is warm and comfortable enough for the climate
• Consider the air temperature and humidity in your bedroom
• Keep clean and easy-to-put-on clothes nearby, just in case of emergencies
• Wash your bed sheets more frequently

Summary

There is no definitive answer to whether sleeping with or without clothes is healthier, as both options come with their pros and cons. That’s why it’s better to make a choice based on your personal comfort and preference. What matters more is the quality of your sleepwear and bedding. Don’t skimp on good fabrics and breathable sheets. Remember, you spend a significant portion of your life in bed. 

Nevertheless, there’s no harm in giving it a try, especially if you struggle with falling asleep or have insomnia; sleeping naked might offer some relief. As long as you don’t have any of the specific conditions mentioned above, go ahead – try it out and see how your body responds.