The Influence of Temperature on Sleep and Dreams

Sep 22, 2023 | Blog, Health

Temperature is not just about comfort; it plays a pivotal role in determining the quality of our sleep. Have you ever wondered why on some nights you are restless, but on others, you fall asleep effortlessly? The secret might be in your thermostat.

The Goldilocks Principle of Sleep

When the environment is too hot or too cold, our sleep cycle feels the jolt. The deep sleep stages, REM and slow wave sleep, are crucial for rejuvenation.1 Excessive warmth can curtail these stages. Interestingly, a chilly room does not have the same effect, as long as we are cozily tucked in.2 What we wear to bed and the bedding we choose can also affect how temperature influences our sleep. A light pajama might leave us vulnerable to the cold, but a warm blanket can fend off its effects. Yet, regardless of our bedtime attire, heat remains a persistent sleep interrupter.

The Impact of Temperature on Sleep and Health

A sweltering environment, especially when paired with humidity, can be the nemesis of peaceful sleep. It leads to frequent awakenings and diminishes the quality of deep sleep.2 This is our body’s SOS, signaling that it is straying from its comfort zone. Sweating is our built-in air conditioner.3 But when the air is thick with moisture, this cooling sweat does not evaporate as it should, making us feel even toastier. It is also worth noting that as we grow older, our sleep becomes more susceptible to these disturbances.

Heat can sometimes influence our dreams. Fever dreams are a curious phenomenon many experience when running a high temperature. As the body’s internal thermostat rises due to illness, it can influence not only our physical well-being but also our dream content. The heat can intensify brain activity during the REM (Rapid Eye Movement) stage of sleep, where most dreaming occurs.4 This heightened activity, combined with the body’s response to illness, can lead to vivid, often bizarre, and sometimes unsettling dreams. These dreams, commonly referred to as “fever dreams,” are a testament to the intricate connection between our body’s temperature and our brain’s dream-producing mechanisms.

Cold temperatures, while often associated with cozy nights under blankets, have a deeper impact on our sleep than we might realize. These temperatures directly influence our heart rhythm, which can have implications for our overall health. There is a noticeable increase in heart-related issues during the colder months, suggesting a correlation between cold environments and cardiovascular health. When you feel cold, the blood vessels in your skin, fingers, and toes constrict to reduce heat loss. However, this constriction, known as ‘vasoconstriction’, increases pressure in the overall circulatory system. As a result, the heart must exert more effort to circulate blood throughout the body, leading to a rise in heart rate and blood pressure.5 While we often rely on our blankets, duvets, and heaters to create a warm and comfortable sleeping environment, it is crucial to be aware of the broader health implications of cold temperatures. Ensuring a balanced room temperature can not only promote better sleep but also safeguard our heart health.

Understanding Our Body’s Internal Timekeeper

The circadian rhythm, often referred to as our body’s internal clock, plays a pivotal role in determining our sleep-wake cycles. While light exposure is the primary factor that sets this rhythm, temperature too has a significant influence. As the temperature rises or drops, our body can experience shifts in its sleep patterns.2 This is especially pronounced when temperature changes coincide with variations in light exposure, such as during the transition from summer to winter or vice versa. Being aware of these factors and adjusting our environments accordingly can help in achieving a more restful and rejuvenating sleep.

Tips for a Temperature-Tuned Sleep

In the grand scheme of things, understanding the dance between temperature and sleep can be the key to better rest. By making small adjustments and being attuned to these nuances, we can pave the way for nights of deep sleep and days brimming with energy.

  1. Thermostat Tricks: Aim for a bedroom temperature between 60 to 67 degrees Fahrenheit. This range is generally considered ideal for sleep.6
  2. Layer Up: Use layers of bedding that can be easily added or removed. This way, you can adjust your warmth level as needed.
  3. Cooling Bedding: Consider investing in cooling pillows or sheets, especially if you tend to overheat at night.
  4. Warm Footwear: Cold feet can be a sleep disruptor.7 Wearing socks or using a hot water bottle can help.
  5. Stay Hydrated: Drink enough water throughout the day. Dehydration can make it harder for your body to regulate its temperature.8

By understanding the effects of temperature on our sleep patterns, we can make informed choices to optimize our sleeping conditions. Whether it is adjusting our room’s thermostat, investing in the right bedding, or simply being aware of seasonal changes, every step brings us closer to achieving restful nights. After all, a good night’s sleep is not just about rest—it is about rejuvenating our minds, bodies, and spirits for the challenges of tomorrow.

Learn More

Sleeping well is pivotal for our overall well-being and mental sharpness. If restful nights elude you, it might be the right moment to seek expert guidance. Somnology’s comprehensive sleep services and data monitoring platform are engineered to provide everyone involved in the sleep care journey – from patients and care providers to healthcare payors and employers – with the information they need to improve health outcomes. With our innovative offerings like the SLaaS® (Sleep Lab as a Service) platform, telemedicine services, the SomnoRing®, and the SomnologyMD mobile app, we are revolutionizing the sleep care experience. We bring the sophistication of a sleep lab right to your fingertips, placing you, the patient, at the heart of everything we do. We are here to guide you every step of the way on your journey to better sleep. To discover more about how we can help you, visit our website.


  1. Cleveland Clinic. “Sleep Basics.” Cleveland Clinic.
  2. Okamoto-Mizuno, Kazue, and Koh Mizuno. “Effects of thermal environment on sleep and circadian rhythm.” Journal of Physiological Anthropology 31, no. 1 (2012): 14. NCBI.
  3. Gagnon, D., & Crandall, C. G. (2018). Sweating as a heat loss thermoeffector. Handbook of Clinical Neurology, 156, 211–232. PubMed.
  4. Sleep Foundation. “What Are Fever Dreams? Causes and Meaning.” Sleep Foundation.
  5. British Heart Foundation. “How does cold weather affect your heart?” BHF.
  6. Cleveland Clinic. “What’s the Best Temperature for Sleep?” Cleveland Clinic.
  7. Ko, Y., Lee, JY. Effects of feet warming using bed socks on sleep quality and thermoregulatory responses in a cool environment. J Physiol Anthropol 37, 13 (2018). Journal of Physiological Anthropology.
  8. Healthline. “Can Dehydration Lead to Insomnia?” Healthline.