While it might not be immediately apparent, your body and brain work tirelessly while you rest to repair cells, process information, and remove toxins, among other tasks. It’s hard work, but that doesn’t mean you should be working up a sweat while you sleep—although many people do.
Your body temperature decreases before bedtime, reaching its lowest point in the sleep cycle’s initial stages, known as the non-rapid eye movement (NREM) period. Ideally, it should remain lower throughout the night to help you get the quality, restorative shuteye you need. But for many people, things don’t go so smoothly. If you’re consistently waking up overheated, uncomfortable, and drenched in sweat, one of a few factors may be to blame.
Sharing the bed with a partner or pet can be nice, but the extra warmth from another body may be too hot for you to handle. This doesn’t mean you have to sleep in separate beds. If your mattress is too small to provide sufficient room for both of you to sleep comfortably in your own space, simply consider going up a size.
This could be Mother Nature’s fault or a product of differences in thermostat preference between you and other household members. The former is an issue during warmer months for people in most regions, but especially those in the Sun Belt, where temperatures frequently climb into the triple digits with intense humidity levels to match. Utilizing fans, turning up the air conditioner if you have one, and opening the windows at night to allow cooler air to filter in can all provide relief.
If you’re too warm because someone else in your household keeps the heat cranked up, consider investing in a smart heating and cooling system that can produce different temperatures for different rooms. If the discrepancy is with your partner, it might be harder to mitigate. Your natural internal temperature is affected by a wide range of factors, including age, weight, sex, and even activity levels. Solutions for a partner temperature mismatch can include warmer or cooler pajamas and customized pillows.
Your metabolic rate is the speed at which your body burns through calories. This process raises your internal temperature, so those with faster metabolism often tend to be warmer. On average, many men have higher metabolic rates than women. Your metabolic rate can also shift throughout your life due to things like age or a change in activity levels. As these shifts occur, you may find your sleep temperature affected.
Hormone fluctuations, including those related to menstruation, can cause excessive warmth too. Changes in reproductive hormones affect the hypothalamus, which controls the body’s temperature. Menopause is known to cause significant temperature changes and hot flashes. Some people also have an underactive or overactive thyroid, a gland that produces hormones and affects your metabolism. Those with thyroid issues are likely to experience significant temperature variations.
If you’re overheating every night, mattresses and bedding may also be part of the problem. Memory foam, in particular, tends to run hot. It is typically made from a dense, synthetic material that doesn’t absorb moisture or ventilate efficiently. The foam’s body-contouring properties, which make it excellent for support, can also trap body heat. Similarly, sheets made with synthetic materials tend to be less breathable when compared to cotton or bamboo.
Consider choosing natural-fiber sheets and a mattress made with cooling technology. Many mattress manufacturers now incorporate advanced ventilation and temperature-regulation systems to prevent overheating and promote optimal comfort.
The original memory foam mattress, devised by NASA and adapted by Swedish scientists for the public, was viscoelastic. Many companies still use this material today, but there are other foams available too.
Viscoelastic material is absorbent and soft, conforming to the sleeper’s body in response to pressure and heat. This is particularly useful for people with chronic pain or musculoskeletal conditions, because these mattresses offer support and cushioning where they’re needed most.
Painful, inflamed areas of the body tend to produce more heat due to increased blood flow. The mattress responds to this by cradling these areas to relieve pressure points and promote optimal balance. The caveat is that it also traps and collects this body heat.
Fortunately, a lot of research goes into sleep, and many innovative mattress-makers have come up with solutions to the problem of trapped heat. Some mattresses contain air pockets or channels within their layers, which promote ventilation. Others are made with unique temperature-regulating materials, either within the mattress or in the form of a cover or topper.
Mattress companies are continually experimenting with different combinations of these materials. The resulting mattresses, called hybrids, can offer superior support and temperature regulation. Some of the top hybrid models on the market today include:
In addition to creating combinations of existing materials, mattress manufacturers also innovate constantly to find new materials and methods that will provide sleepers with more comfortable and quality shuteye. Some keep their technologies under lock and key, while others release their proprietary products for market-wide use, like the original memory foam inventors.
Cooling mattress pads and toppers are designed to absorb moisture and body heat, and they work best in conjunction with a temperature-neutral bed rather than alone. If you use a cooling topper or pad on top of a standard memory foam mattress, much of your body heat may still be absorbed by the bed beneath, limiting the pad or topper’s effectiveness. Many mattresses come with mattress pads or toppers equipped with cooling technology, but you can also purchase one separately.
Your body temperature plays an essential role in the quality of your nightly rest, which in turn affects how you feel the next day. Investing in sleep-enhancing items like a cooling mattress and bed accessories can help you enjoy more restful nights and easier, more energized days. When shopping for any of the above items, be sure to look at customer reviews and review the company’s return policies and warranties to ensure you get the best deal for your money.