If you frequently get hot while sleeping, you're not alone. Many people feel perfectly cool when they climb into bed, only to wake up a few hours later uncomfortably warm or drenched in sweat. The reasons why you sleep hot vary from person to person—including underlying health conditions—but the solutions are more practical than you might think.
6 Common Causes for Sleeping Hot at Night
1. You Have a High Metabolism
Your metabolism doesn’t just burn calories—it also produces heat. As your body converts food and stored energy into fuel for essential functions, some of that energy is released as heat. In general, a higher metabolic rate means greater metabolic heat production, which can contribute to feeling warmer than someone whose body is using less energy at rest.
This can matter at bedtime because falling asleep normally coincides with a drop in core body temperature. During sleep, metabolic heat production typically decreases while the body shifts heat toward the skin so it can dissipate into the environment. If you tend to generate more body heat or your bedding and bedroom make that heat difficult to release, you may be more likely to feel uncomfortably warm at night.
2. You Exercise Too Close to Bedtime
Working out too close to bedtime can also make it hard to get cool and comfortable. Exercising raises your core body temperature because working muscles produce substantial heat. After you finish a workout, your body begins releasing that excess heat, but cooling back down takes time. If you exercise close to bedtime, especially if the workout is long or vigorous, you may still be warmer than usual when you get into bed.
Exercise can also temporarily increase your metabolic rate, circulation, and sweating as your body works to return to its resting state. Because sleep onset is normally associated with a decline in core body temperature, this lingering heat can leave you feeling hot or sweaty under the covers.
3. Your Hormones Are Fluctuating
Changes in reproductive hormones affect the hypothalamus, your body's internal thermostat. For women, these fluctuations are especially common during menstruation (often causing noticeably hotter nights in the days before a period), pregnancy, and menopause.
Perimenopause and menopause are among the most frequent causes of night sweats and hot flashes. According to Harvard Health Publishing, up to 85% of women experience hot flashes during the menopause transition. If you're in this stage, your mattress choice matters more than ever.
4. It’s a Medication Side Effect
Some prescription drugs—including diabetes medications, hormone-blocking drugs, migraine treatments, antidepressants, and other psychiatric medications—can sometimes cause higher body temperatures and excessive sweating both during the day and at night. Stopping the use of certain medications can also lead to sweating and other withdrawal side effects.
If overheating or night sweats are disrupting your sleep and you suspect it’s related to your medication, be sure to discuss these symptoms with your healthcare provider.
5. Your Sleep Environment Is Too Warm
Room temperature, humidity, and even your bedding materials significantly affect sleep temperature. The ideal sleep environment is between 60–67°F (15–19°C). Thick duvets, synthetic sheets, and mattresses that trap heat all raise the ambient temperature around your body overnight.
6. You’re Sleeping on an Outdated or Low-Quality Foam Mattress
If you’ve ruled out your own body or your bedroom temperature as possible causes of getting too hot at night, the problem could very well be your mattress. Some mattress materials—particularly certain types of foam—don’t have good airflow and therefore absorb and trap body heat. The result? A sweaty, uncomfortable night with very little sleep.
Practical Tips to Help You Stay Cool Overnight
If you regularly wake up sweaty, kick off the covers, or struggle to fall asleep because you feel too warm, a few changes to your sleep environment and bedding may help. The best solution depends on why you’re overheating in the first place, but these practical steps can help create a cooler, more comfortable setting for sleep.
Talk to Your Doctor About Any Underlying Issues
Sometimes, sleeping hot has less to do with your bedroom and more to do with what’s happening in your body. Hormonal changes, certain medications, illness, and other health conditions can contribute to night sweats or make it harder for your body to regulate its temperature.
If sleeping hot is new, persistent, severe, or accompanied by other symptoms, consider talking with your healthcare provider. They can help determine whether an underlying issue could be contributing to the problem and recommend appropriate next steps.
Leverage Your AC, Windows, Fans, or Dehumidifiers
Aim to keep your bedroom around 60º–67ºF throughout the year. Because outdoor conditions change from season to season, maintaining that range may require a combination of heating, cooling, ventilation, and humidity control.
During warmer months, use your air conditioner to cool the bedroom before bedtime and maintain a comfortable temperature overnight. Ceiling or portable fans can improve air circulation and create a cooling effect, while blackout curtains or shades can help prevent daytime sunlight from heating the room. When evenings are cooler than the indoor temperature, opening windows can also help release accumulated heat and bring cooler air inside.
In colder months, avoid overheating the bedroom with your furnace or other heating system. Lowering the thermostat at night can help keep the room within the 60º–67ºF range, while your bedding can provide additional warmth as needed. If the room becomes too cold, adjust the heat gradually rather than relying on especially heavy bedding that may trap excess body heat.
Humidity can affect how comfortable a given temperature feels as well. High humidity makes it harder for sweat to evaporate efficiently, so a dehumidifier may make warm or muggy bedrooms more comfortable. By monitoring both temperature and humidity—and adjusting your HVAC system, windows, fans, and dehumidifier accordingly—you can create a consistently cool sleep environment in any season.
Switch to More Breathable Bedding
Your sheets, blankets, pillows, and sleepwear can all affect how much heat gets trapped around your body. If your bed feels stuffy or warm, consider replacing heavy or less breathable materials with options designed to promote airflow and manage moisture.
Natural fibers such as cotton and linen are popular choices for hot sleepers because they're generally breathable. Some bedding also incorporates moisture-wicking or temperature-regulating materials like Tencel™, designed to move moisture away from the body or reduce heat buildup.
Don't overlook your comforter or duvet, either. A lightweight blanket or lower-fill comforter may be more comfortable during warmer months than thick, insulating bedding. Layering lighter bedding also makes it easier to adjust your covers throughout the night.
Upgrade to a Mattress with Cooling Properties
If you've optimized your room and bedding but still wake up feeling overheated, your mattress could be part of the problem. Some mattress materials retain more body heat than others, while mattresses designed with airflow and temperature regulation in mind can help minimize heat buildup around the sleeper.
What Mattress Features Help Keep You Cool?
If you’re shopping for a mattress for hot sleepers, look beyond claims that a bed simply "sleeps cool." The mattress's construction and materials can provide a better indication of how it may perform throughout the night.
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Breathable Construction: Mattresses with plenty of room for air to circulate can help prevent heat from accumulating. Hybrid mattresses often perform well in this area because their coil systems leave more open space for airflow than dense foam cores.
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Temperature-Regulating Materials: Some mattresses incorporate cooling covers, phase-change materials, gel-infused foams, copper-infused foams, or other technologies intended to absorb, redistribute, or dissipate heat. The effectiveness of individual technologies varies, so it's worth considering the mattress as a whole rather than relying on a single cooling feature.
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Comfort Layers That Don't Trap Excessive Heat: Old-school memory foam is known for closely contouring to the body, which can sometimes limit airflow and retain warmth. Newer, more breathable foams or natural latex may offer pressure relief while allowing more heat to escape.
Ultimately, cooling performance comes from the combination of the mattress's cover, comfort layers, support system, and overall construction. Pairing a breathable mattress with lightweight bedding and a comfortably cool bedroom can give hot sleepers the best chance of staying comfortable throughout the night.
Cooling Sleep Comfort with Bear
Bear mattresses use a combination of breathable construction and temperature-regulating materials to help limit heat buildup while you sleep. Depending on the model, these cooling technologies can include phase change material (PCM), copper-infused memory foam, breathable coil systems, and Celliant® covers designed with temperature regulation in mind.
Our Best Cooling Mattress: The Elite Ultra Hybrid
For those who want our best cooling mattress overall, we recommend the Bear Elite Ultra Hybrid. It's our most advanced cooling bed, combining several cooling technologies in one design. Its CoolForce™ Layer uses phase change material to draw excess heat away from the body, creating a cool-to-the-touch surface.
Below that layer, copper-infused memory foam is designed to contour to the body while drawing away heat, while individually wrapped microcoils and an 8-inch zoned coil core provide open space for airflow through the mattress. The Elite Ultra Hybrid also features a Celliant® Infrared Cover, which supports natural temperature regulation.
Together, these technologies address temperature from several angles. That combination makes the Bear Elite Ultra Hybrid our top choice for sleepers who tend to overheat and want Bear's most comprehensive cooling design.
Disclaimer: Bear does not provide medical advice. All resources on the Bear blog, including this article, are informational only and do not replace professional medical counsel. Talk to your doctor about any health, mental health, or sleep-related issues.
