What Is the Best Temperature for Sleep?

By Brandon Peters, MD

It can be a common battleground for couples who sleep together: What is the best temperature for sleep? Whether you are fighting over a thermostat setting, disagree on the best bedding or sleep attire, or are tugging or throwing covers from one side of the bed to the other, the effects of the bedroom temperature may be important. It may even cause insomnia. Learn the optimal room temperature for sleep, what to do if it is too warm or too cold at night, how to sleep better if the temperature is uncomfortable in the summer or winter, and what medical conditions may make it hard to regulate body temperature at night.

The Effects of the Bedroom Environment on Sleep

First, consider what makes for an ideal bedroom environment. Beyond reserving it as a space for sleep and removing electronics, including bright screens, it is also important to consider the roles of noise, light and temperature. As a general, the bedroom should be quiet, dark, and a cool but comfortable temperature. Why might this be?

Consider how you would be sleeping if you did not have a modern home. Imagine as it was 40,000 years ago, living as a Neanderthal. Normal bodily processes, including sleep and temperature regulation, would be closely tied to the natural environment. When it becomes dark and starts to cool off, your body temperature also drops and you would get sleepy and lie down for the night. These same patterns persist in the present day, driven by genetic and environmental factors.

The body temperature reaches its lowest point about 2 hours before your normal wake time. This means if you usually wake up at 6 a.m., your minimum core body temperature will occur at 4 a.m. If you have ever stayed up through the night, you may have noticed how cold you feel at this time. Most of the time we are asleep, however. Towards morning, as the sun approaches the eastern horizon, our body temperature starts to increase, following a consistent circadian (“near day”) pattern.

The pairing of our body temperature to the temperature of the environment helps to minimize heat loss overnight. It may promote normal features of sleep, including the patterns of deep and REM sleep. But what is the best temperature for sleep?

What is the Ideal Bedroom Temperature?

Sleep experts at the National Sleep Foundation recommend that there is an ideal bedroom temperature range to promote healthy sleep. These ranges may vary somewhat based on age. Consider these recommendations:

• Babies and toddlers: 65 to 70 degrees Fahrenheit (18 to 21 degrees Celsius)

• Children and adults: 60 to 67 degrees Fahrenheit (15 to 19 degrees Celsius)

It may be best to use a smart thermostat to regulate the temperature of your home, turning down the temperature setting overnight. A degree variation from these recommendations, higher or lower, likely has little effect. Though these suggestions may be comfortable for most people, respect your body. If you feel too cool, or too warm, you may have to make some adjustments.

What If It Is Too Cold?

If you sleep in an environment that is too cold at night, your body will have to work to maintain your core body temperature at the desired level. This may provoke shivering, as the muscles of the body contract to produce warming energy. Feeling cold at night may also provoke awakenings. This may be helpful to make changes in the environment, such as pulling up covers or snuggling close to a bed partner. Unfortunately, it may also contribute to poor sleep quality and insomnia.

In extreme scenarios, such as sleeping unprotected in the woods with inadequate clothing, may provoke a serious decrease in the body temperature that can lead to hypothermia and even death due to exposure.

What If It Is Too Warm?

Almost everyone has experienced a night when their bedroom was too warm, making it hard to fall asleep. This may occur in the summer on especially hot days. What occurs when the bedroom is too warm at night?

Not surprisingly, the most common side effect of feeling too warm at night is sweating. The body regulates its temperature by increasing blood flow to the periphery (including to the hands and feet). It also promotes evaporative cooling by causing sweating. Just like during wakefulness, sweating may start in the hair of the head, armpits, and groin. If additional cooling is needed, the torso (chest, abdomen, or back) or extremities (arms and legs) may become slick with sweat.

Beyond feeling sweaty, there may be restless sleep with frequent awakenings and position changes contributing to insomnia. Attempts may be made to flip a pillow over to its cool side, to throw off covers, or to move away from a bed partner. It may be necessary to remove clothing, such as shedding warm pajamas or other sleep attire. It may help to open a window overnight, so the natural cooling of the environment can occur in the bedroom as well. In some cases, major adjustments may be necessary, including changes in the mattress or pillow (such as avoiding memory foam) to improve temperature regulation during sleep.

If the body temperature increases to a dangerous level, the effects of the resulting fever may cause serious consequences, including loss of consciousness, seizures, coma, and even death.

What About Humidity?

Beyond temperature, it is also important to consider the effects of humidity on sleep. When air is cold, or warm, there are changes in the amount of moisture that the air contains. In the winter, colder air may be more dry and this may affect the ability to breathe optimally during sleep. This may lead to nasal dryness or congestion, increasing snoring or sleep apnea, or even may make it more likely to develop upper respiratory illnesses like colds or influenza. Humidifier use, especially in a dry climate, may make it more comfortable to breathe at night and this may improve sleep. 

How to Sleep Better During Cold Weather 

What should you do if you are having difficulty sleeping due to a bedroom that is too cool? This may be more likely during cold weather during the winter months. It may also occur if you share a bedroom with someone who prefers a cooler temperature. Consider these options:

• Wear warmer pajamas (think flannel)

• Use extra blankets or an electric heated blanket

• Put heavier bedding on the bed (such as a heavy comforter or duvet)

• Turn up the thermostat

• Consider a space heater (kept away from flammable materials and with a safety timer feature to automatically turn off)

• Cuddle with a bed partner or pet

• Wear warm socks to bed

• Drink a warm beverage before bedtime (but avoid caffeine)

• Take a hot shower or bath prior to coming to bed

• In some cases, you may need to sleep in a different bedroom from someone who has a starkly different temperature preference at night.

How to Sleep Better During Warm Weather 

What if it is just too hot at night? Fortunately, there may be some helpful interventions to cool off at night when the weather gets too warm. Review these suggestions:

• Choose light, breathable sleep attire (such as cotton) or sleep naked

• Remove heavy blankets and bedding and consider using just a sheet

• Set up a circulating fan near the bed

• Use the air conditioning overnight

• Take a cool shower or bath prior to bedtime

• Leave the windows open at night

• Avoid artificial memory foam mattresses or pillows

• Consider the use of cooling devices (including pillows, sheets, pads, or even headgear)

If the unpleasant weather is due to a summer heat wave, hopefully it breaks quickly and your sleep will promptly return to normal as it does.

Is Poor Temperature Regulation a Medical Condition?

It is normal to question whether a difficulty regulating the body temperature at night is due to a medical condition. In some cases, such as an acute illness associated with a fever, it clearly is. There may be other chronic medical conditions that affect temperatures at night as well.

The most common conditions that impact the body temperature overnight are related to hormones. Thyroid problems often cause sweats or chills, correlating with hyperthyroidism or hypothyroidism, respectively. In addition, night sweats may be linked to the hormonal changes of menopause.

Sweating may occur due to the side effects of some medications. Sleep disorders such as sleep apnea can lead to frequent sweats due to the associated bursts of cortisol (stress hormone). Obesity, anxiety, and even hypoglycemia may cause sweats at night.

There are rare conditions that can cause elevated temperatures at night, including infectious diseases like tuberculosis and even some cancers. If the temperature regulation problems persist without explanation, especially in the context of other symptoms, it may be worth getting checked out. 

Conclusion

If you have difficulty sleeping comfortably at night, review whether you can make some changes to help yourself to sleep better. If you struggle with chronic insomnia, consider cognitive behavioral therapy for insomnia (CBTI). Fortunately, speaking with a board-certified sleep physician can often provide you the answers you need to sleep normally throughout the year, tolerating the normal variation of nighttime temperatures.

Sources:

Troynikov O, et al. “Sleep environments and sleep physiology: A review.” J Therm Bio. 2018 Dec;78:192-203. doi: 10.1016/j.jtherbio.2018.09.012. Epub 2018 Oct 5.

Szymusiak R. “Body temperature and sleep.” Handb Clin Neurol. 2018;156:341-351. doi: 10.1016/B978-0-444-63912-7.00020-5. 

Roth T, et al. “A novel forehead temperature-regulating device for insomnia: a randomized clinical trial.” Sleep. 2018 May 1:41(5). doi: 10.1093/sleep/zsy045.

Lappharat S, et al. “Effects of Bedroom Environmental Conditions on the Severity of Obstructive Sleep Apnea.” J Clin Sleep Med. 2018 Apr 15;14(4):565-573. doi: 10.5664/jcsm.7046.

Kryger MH, et al. Principles and Practice of Sleep Medicine. ExpertConsult, 6th edition, 2017.

Could Falling Asleep Too Fast Be a Sleep Problem?

Falling asleep quickly may seem like a blessing, particularly for those who struggle with insomnia or other sleep disturbances. However, falling asleep too fast can sometimes signal underlying sleep problems or health issues. In this article, we'll explore what it means to fall asleep quickly, the potential causes and implications, and how to assess whether it is a concern for you.

Understanding Sleep Onset

Sleep Onset Latency

Sleep onset latency (SOL) refers to the amount of time it takes to transition from full wakefulness to sleep. A typical SOL is usually between 10 to 20 minutes for adults. If you consistently fall asleep in less than five minutes, it may raise questions about your sleep health.

Individual Variability

It’s important to recognize that sleep patterns vary from person to person. Factors such as age, lifestyle, stress levels, and overall health can influence how quickly one falls asleep. Some individuals may naturally have a shorter SOL due to their unique physiology or lifestyle habits, while others may take longer. The most common cause of falling asleep quickly is likely recent sleep deprivation, and most adults need 7 to 9 hours of sleep with a consistent sleep-wake schedule to feel rested.

When Falling Asleep Quickly Is a Concern

Excessive Daytime Sleepiness

If you find yourself falling asleep quickly not only at night but also during the day—such as in meetings, while watching TV, or even while driving—it could indicate excessive daytime sleepiness (EDS). This condition can be a symptom of various sleep disorders, including:

• Obstructive Sleep Apnea (OSA): A condition where breathing repeatedly stops and starts during sleep, leading to poor sleep quality and daytime drowsiness.

• Narcolepsy: A neurological disorder characterized by uncontrollable episodes of daytime sleepiness and sudden sleep attacks.

• Hypersomnia: A condition where an individual experiences excessive sleepiness during the day, often unrelated to nighttime sleep quality.

Poor Sleep Quality

Falling asleep quickly could also indicate that the quality of your sleep is compromised. If you fall asleep instantly but wake up frequently during the night, struggle to stay asleep, or feel unrefreshed upon waking, it may point to an underlying issue. Factors contributing to poor sleep quality can include:

• Stress and Anxiety: High levels of stress can disrupt your sleep cycle, leading to a quick fall asleep but shallow or disturbed sleep.

• Substance Use: Alcohol, caffeine, and certain medications can alter sleep patterns and affect sleep quality, causing rapid onset of sleep but leading to unrestful nights.

Sleep Disorders

Certain sleep disorders can contribute to rapid sleep onset. If you find yourself consistently falling asleep quickly in situations where you would prefer to stay awake, consider the possibility of a sleep disorder. Some common conditions include:

• Sleep Apnea: Frequent waking during the night due to breathing interruptions can result in excessive daytime sleepiness, making it easier to fall asleep quickly at night.

• Restless Legs Syndrome (RLS): Characterized by an uncontrollable urge to move your legs, particularly at night, leading to difficulties in falling asleep. It may be associated with leg movements during sleep, called periodic limb movements of sleep (PLMS), a disorder that fragments sleep and reduce its quality.

• Circadian Rhythm Disorders: Disruptions in the body’s internal clock can lead to inappropriate sleep timing, resulting in either excessive sleepiness or difficulty staying awake.

Factors Contributing to Fast Sleep Onset

Lifestyle Factors

1. Sleep Hygiene: Poor sleep hygiene practices can lead to disrupted sleep patterns. Factors such as inconsistent sleep schedules, excessive screen time before bed, and an uncomfortable sleep environment can all contribute to how quickly you fall asleep.

2. Physical Activity: Regular exercise can promote better sleep quality. However, excessive fatigue from overexertion may lead to faster sleep onset without necessarily achieving restful sleep.

3. Diet: Consuming heavy meals or stimulants close to bedtime can affect sleep quality. On the other hand, a lack of nutrients can lead to fatigue, resulting in quicker sleep onset.

Psychological Factors

1. Mental Health: Anxiety, depression, and other mental health conditions can impact sleep patterns. While some individuals may experience insomnia, others may fall asleep quickly due to overwhelming exhaustion or depressive symptoms.

2. Stress Management: Chronic stress can lead to fatigue, making it easier to fall asleep quickly. However, this type of sleep is often shallow and not restorative.

Medical Conditions

1. Chronic Fatigue Syndrome: This condition is characterized by extreme fatigue that does not improve with rest. Individuals may fall asleep quickly due to exhaustion but experience unrefreshing sleep.

2. Thyroid Issues: An underactive thyroid (hypothyroidism) can lead to fatigue and sleepiness, contributing to rapid sleep onset.

When to Seek Help

If you consistently find yourself falling asleep in under five minutes and experience any of the following, it may be time to consult a healthcare professional:

• Daytime Drowsiness: If you struggle to stay awake during the day or find yourself napping frequently, it could be a sign of a sleep disorder.

• Frequent Night Wakings: Waking up multiple times during the night can affect sleep quality and overall health.

• Morning Fatigue: Waking up feeling unrefreshed, regardless of how long you’ve slept, may indicate an issue with your sleep quality.

Assessing Your Sleep Health

Sleep Diary

Keeping a sleep diary can help you monitor your sleep patterns. Record the time you go to bed, how long it takes to fall asleep, how often you wake up during the night, and how you feel in the morning. This information can be valuable for identifying patterns and discussing them with a healthcare professional.

Sleep Study

In some cases, a sleep study (either a home sleep apnea test or in-center polysomnography) may be necessary to diagnose underlying sleep disorders. These tests monitor various body functions during sleep, including brain activity, heart rate, and breathing patterns.

Professional Consultation

If you have concerns about your sleep patterns or experience any of the symptoms mentioned above, it’s advisable to consult a healthcare provider or a sleep specialist. They can provide a thorough assessment, offer potential diagnoses, and suggest appropriate treatment options.

Conclusion

While falling asleep quickly can seem like a gift, it can also indicate underlying issues that deserve attention. Understanding the potential implications and being aware of your overall sleep health is essential. Whether it’s lifestyle changes, psychological factors, or underlying medical conditions, addressing the root causes can lead to better sleep quality and overall well-being. If you find that rapid sleep onset negatively affects your daytime functioning or quality of life, consider seeking professional guidance for a more comprehensive evaluation. Sleep is vital for our physical and mental health, and ensuring you get quality rest is essential for thriving in daily life.

This article was created using OpenAI’s ChatGPT on September 19, 2024 and it was personally reviewed and edited by Brandon Peters, M.D. to ensure its accuracy. This use of augmented intelligence in this way allows the creation of health information that can be trusted.

Can Hypothyroidism Cause Obstructive Sleep Apnea?

Obstructive sleep apnea (OSA) is a common sleep disorder characterized by repeated interruptions in breathing during sleep due to the relaxation of the throat muscles. This condition can lead to various health complications if left untreated, including cardiovascular problems, daytime fatigue, and cognitive impairments. While obesity is a well-known risk factor for OSA, other underlying health issues may also contribute to its development. One such condition is hypothyroidism, a disorder in which the thyroid gland does not produce enough thyroid hormones. This article explores the relationship between hypothyroidism and obstructive sleep apnea, including potential mechanisms and implications for treatment.

Understanding Hypothyroidism

Hypothyroidism occurs when the thyroid gland, located in the front of the neck, does not produce sufficient amounts of thyroid hormones, primarily thyroxine (T4) and triiodothyronine (T3). These hormones play a crucial role in regulating metabolism, energy production, and various bodily functions. Common causes of hypothyroidism include:

Autoimmune Disorders: Hashimoto's thyroiditis is the most common cause of hypothyroidism, where the immune system attacks the thyroid gland.

Thyroid Surgery: Surgical removal of the thyroid can lead to reduced hormone production.

Radiation Therapy: Treatment for thyroid cancer or other head and neck cancers can damage the thyroid gland.

Iodine Deficiency: Iodine is essential for thyroid hormone production, and a deficiency can lead to hypothyroidism.

Symptoms of hypothyroidism can include fatigue, weight gain, cold intolerance, constipation, dry skin, and depression. However, the relationship between hypothyroidism and obstructive sleep apnea is less well understood. If hypothyroidism is severe, stupor and coma may occur.

The Connection Between Hypothyroidism and Obstructive Sleep Apnea

Research suggests that there is a significant association between hypothyroidism and obstructive sleep apnea. Several studies have indicated that individuals with hypothyroidism are at an increased risk of developing OSA. Here are some potential mechanisms that may explain this relationship:

1. Thyroid Hormones and Muscle Tone: Thyroid hormones play a crucial role in maintaining muscle tone and metabolism throughout the body, including the muscles of the upper airway. Hypothyroidism can lead to muscle weakness and reduced muscle tone, making it more likely for the airway to collapse during sleep. This collapse can result in obstructive apneas, where breathing is interrupted due to obstruction in the upper airway as the tongue blocks the throat.

2. Obesity and Metabolism: Hypothyroidism often leads to weight gain due to a slowed metabolism. Increased weight, particularly when fat tissue is deposited at the base of the tongue, can contribute to airway obstruction during sleep. Fat deposits in the neck can also lead to increased pressure on the airway, exacerbating sleep apnea symptoms. The relationship between obesity and OSA is well established, and since hypothyroidism can lead to weight gain, it serves as an indirect contributor to the development of sleep apnea.

3. Fluid Retention and Edema: Hypothyroidism can cause fluid retention, leading to swelling in various parts of the body, including the throat. This swelling can further narrow the upper airway, increasing the likelihood of obstruction during sleep. Edema in the airway tissues can contribute to increased resistance to airflow, making it more challenging to breathe properly during sleep.

4. Decreased Respiratory Drive: The thyroid hormones also play a role in the regulation of the respiratory drive. In hypothyroid patients, decreased levels of thyroid hormones can lead to a reduced response to changes in oxygen and carbon dioxide levels in the blood. This can impair the body’s ability to initiate breathing during apneic episodes, exacerbating the severity of OSA.

5. Neurological Factors: There is evidence to suggest that hypothyroidism can affect the central nervous system, potentially leading to changes in the regulation of breathing patterns during sleep. This dysregulation may contribute to the development or exacerbation of sleep apnea.

Symptoms Overlap

The symptoms of hypothyroidism and obstructive sleep apnea can overlap, making diagnosis challenging. Both conditions can cause excessive daytime sleepiness, fatigue, and cognitive impairments. Individuals with hypothyroidism may already experience fatigue due to hormonal imbalances, which can mask or mimic symptoms of OSA. As a result, it is crucial for healthcare providers to consider the possibility of sleep apnea when evaluating patients with hypothyroidism.

Diagnosis and Treatment Considerations

If you suspect that you have both hypothyroidism and obstructive sleep apnea, it is essential to consult with a healthcare provider. Diagnosis may involve a combination of clinical evaluations, sleep studies (home sleep apnea testing or in-center polysomnography), and thyroid function tests to measure levels of thyroid hormones (T3 and T4) and thyroid-stimulating hormone (TSH).

1. Managing Hypothyroidism: Treatment of hypothyroidism typically involves hormone replacement therapy with levothyroxine, a synthetic form of thyroid hormone. Effective management of hypothyroidism can lead to improved muscle tone and metabolism, which may, in turn, reduce the severity of obstructive sleep apnea.

2. Addressing Obstructive Sleep Apnea: For individuals diagnosed with both conditions, treating sleep apnea is crucial. Treatment options for OSA may include:

-Continuous positive airway pressure (CPAP): This therapy involves wearing a mask connected to a machine that delivers a continuous flow of air, keeping the airway open during sleep.

-Oral appliances: Dental devices can help reposition the jaw and tongue to keep the airway open.

-Lifestyle changes: Weight loss, positional therapy (sleeping on one's side), and avoiding alcohol or sedatives before bedtime can help alleviate symptoms of OSA.

3. Regular Monitoring: Individuals with hypothyroidism and OSA should have regular follow-up appointments to monitor their conditions. Adjustments in thyroid hormone therapy and continuous assessment of sleep apnea treatment efficacy are essential for optimal health outcomes.

Conclusion

Hypothyroidism and obstructive sleep apnea are interconnected conditions that can significantly impact an individual's quality of life. The presence of hypothyroidism may increase the risk of developing OSA through mechanisms such as reduced muscle tone, weight gain, fluid retention, and altered respiratory drive. Given the overlap in symptoms, it is essential for healthcare providers to consider the possibility of sleep apnea in patients with hypothyroidism.

Effective management of both conditions can lead to improved overall health and quality of life. If you suspect you have symptoms of either condition, consult with a healthcare provider for comprehensive evaluation and appropriate treatment options. By addressing hypothyroidism and sleep apnea together, individuals can achieve better sleep quality and overall health.

This article was created using OpenAI’s ChatGPT on August 2, 2024 and it was personally reviewed and edited by Brandon Peters, M.D. to ensure its accuracy. This use of augmented intelligence in this way allows the creation of health information that can be trusted.