Waking up drenched in sweat is unpleasant, to say the least. But hot sleep can be difficult to stave off, particularly when temperatures rise outside.
If you find yourself struggling to sleep cool, you might consider taking a few steps to regulate your sleep environment — including investing in "cooling" sheets, comforters, and pillows. These items won't solve your sleep woes by themselves, but they can certainly help, especially as part of your wider effort to improve sleep hygiene and finally (finally) get a good night's rest.
Why is "sleeping cool" important?
A cool sleep environment doesn't just feel better (though that's certainly true); it's also crucial to sleeping well. Our bodies prepare for and begin the transition into sleep by dropping in temperature, helping us feel drowsy. A cooling pillow can assist in that process.
"To initiate and maintain sleep, our core body temperature needs to drop between two and three degrees Fahrenheit," Christina Pierpaoli Parker, a sleep and health researcher and a resident of clinical psychology at the University of Alabama at Birmingham, told Mashable in an email. "Sleeping cool helps to hasten the body's sleep onset — or the time it needs to fall asleep — and to stay asleep so we can cycle through its deepest stages."
One way to sleep cool, she explained, is to make changes to your thermal environment, or the conditions around you that impact your body temperature.
"When our core body temperature drops at night, the heat gets transferred/distributed to neighboring areas and our nightwear, sheets, and mattresses that absorb and trap it," she said. "Combined with keeping the bedroom dark and cool, light, breathable, and cooling sheets and pillows may aid the thermoregulation the body needs to initiate and maintain sleep."
"Cool," in this case, means between roughly 62 and 70 degrees Fahrenheit, though Parker noted that there's still debate around the precise numbers.
How does a cooling pillow work?
There are a number of approaches designers and engineers can take when designing a cooling pillow, and we've tried to reflect as many as possible in the options below.
First, let's talk covers. In some cases, a breathable cotton or bamboo-based cover will provide a cooler experience than a polyester one, but that's not a sure thing. Moisture-wicking fabrics that are technically polyester (think athletic wear) can be great options too. One cooling pillow on our list, the Layla Kapok Pillow, is infused with copper, which helps stave off the odors caused by sweat. (You may have also seen brands pushing copper-infused face masks to protect against the coronavirus. While copper does have antimicrobial properties, it should not stand in for other hygiene measures in face masks, on pillows, or elsewhere.)
Some pillows are made using phase-change materials, or PCMs, which are designed to regulate temperature, according to the trade publication Home Textiles Today. One of these materials, Outlast, was originally developed for NASA and is used frequently in cooling pillows, including this option from Brookstone.
There's also fill to consider. A solid block of memory foam is often less conducive to cool sleep than smaller, fluffier bits of shredded memory foam, but that's not a sure thing either. Cooling gel, which helps pull heat away from the body, helps regulate temperature in several of our picks, including a memory foam pillow from Tempur-Pedic with panels of cooling gel on both sides.
The one fill we truly discourage for cool sleep is down, which is designed to trap and retain heat.
The protector problem
The most glaring issue with cooling pillows, practically speaking, is that they're largely incompatible with pillow protectors and covers. This applies to PCMs like Outlast as well as cooling gel — when you cover them up with a protector, they're likely not going to feel the same anymore. That doesn't necessarily mean the pillow's effects are gone entirely — a cooling memory foam pillow underneath a case will feel better than a hot down pillow underneath a case — but the experience will probably change.
"When you mention phase-change materials such as Outlast, there is no question that they are soft to the touch. Frankly it is quite amazing," Bill Fish, the general manager of SleepFoundation.org and a certified sleep science coach, explained in an email. "The only problem is that with a pillow, you should be putting both a pillow protector and case on the pillow and once you add those two layers, the fabric is no longer cool to the touch."
One imperfect way to get around this problem is by using a cooling pillow protector or pillowcase. There are lots of well-reviewed options out there, from cooling cotton covers to bamboo pillowcases. Another option is to forgo a pillow protector — just be aware of the costs and benefits.
Not sure which cover/fill combo is right for you quite yet? That's fine. No matter how much you narrow down your sleep profile using guides, studies, and resources, sleep remains a deeply personal experience. It's not totally quantitative. With that in mind, we've noted below which pillows have trial periods, which are separate from a standard warranty and allow you to send the pillow back with no repercussions if it's not a good fit.
Here are our picks for the best cooling pillows. Sleep well!
