How Cutting-Edge Fabrics Keep You Cool When You Start to Heat Up

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From pillows to blankets to entire mattresses, today’s manufacturers offer a wide range of products designed to keep you cool. Unlike heated versions that contain internal systems, cooling fabrics are simply that—fabrics.

So, what’s the magic behind them? How do these products manage to lower your body temperature without any advanced technology? And do they really deliver on their promises?

Cooling Technology Types

The development of cooling fabrics dates back to the early days of NASA, where scientists explored how textiles could influence comfort for astronauts in spacesuits, according to Jim Ross, senior vice president of product development at American Textile Company, creators of Tranquility weighted blankets.

NASA now employs advanced cooling technology in spacesuits, including cooling panels with liquid-filled channels and a network of narrow tubes connected to a refrigeration system in a backpack. This is a far cry from today’s athletic wear options like Nike's Dri-FIT and Adidas Climacool.

"There are various cooling technologies available for textiles," says Ross. These technologies are categorized into two primary types: temperature balance and temperature abatement.

Fabrics that utilize temperature balance rely on wicking. Nike describes how its Dri-FIT technology helps wick sweat and spreads it across the fabric to enable faster evaporation. Similarly, Adidas Climacool works by drawing moisture away from the body in a comparable manner.

These fabrics are typically treated with a polymer, a sequence of organic molecules formed by bonding smaller units known as monomers. The polymer finish is activated by the heat and moisture produced by your body, drawing the moisture away from the fabric's surface, whether it's a sports shirt or leggings.

"It's all about enhancing humidity evaporation," Ross states. He likens temperature balance to the cool feeling we experience after a shower, as the water (or humidity) evaporates from our skin.

On the other hand, temperature abatement works by transferring heat. This type of technology is behind American Textile Company's Tranquility Weighted Blanket. In both instances, the way the textile is treated influences its cooling effects.

With temperature abatement cooling, the fabric actually feels cool to the touch, even though it isn't technically cold. The sensation is created by the conductivity of the fabric's yarn, which consists of highly conductive polyethylene (PE). Unlike wicking technology, which involves a treatment applied to the fabric, in this case, the yarn itself is engineered to cool. PE yarn quickly transfers heat away from the surface.

Ross clarifies that the transfer process is comparable to how different materials such as fabric, wood, and metal feel when touched. For instance, if these materials are placed side by side, the metal will feel cooler, even though the ambient temperature is the same for all three. When you apply heat from your hand, materials like metal will transfer heat away from the surface more quickly, resulting in a cooling sensation. PE yarn operates in this same way.

A blanket that feels cool to the touch and incorporates PE yarn, which is heat-conductive, absorbs body heat and redirects thermal energy, producing a cooling effect. Are you catching the pattern? In both instances, cooling occurs through transference — either heat or humidity is moved away from your body.

We've already discussed two categories of cooling technologies, but there's actually a third — phase change material (PCM). This material can transition — as the name suggests — from a liquid to a solid state based on temperature changes. It either absorbs or releases heat. In textiles or mattresses, PCM helps regulate temperature. For example, the Eli & Elm Whitney Collection bedding is said to provide a cycle of cooling and warming throughout the night, ensuring that the sleeper is never too hot or too cold. This effect is due to small PCM capsules embedded in the fabric fibers.

Which One Is Coolest?

All of the cooling technologies mentioned will serve their purpose effectively. A textile utilizing temperature abatement will provide a cool sensation upon touch, and if you wrap yourself in a cooling blanket, the lower temperature will be easily felt.

With temperature balance, your body undergoes cooling, but in a more gradual and passive manner, according to Ross. Temperature balance continues to cool over a longer period by continually wicking moisture away. One fabric creates a noticeable cool feeling, while the other quietly operates in the background to reduce your temperature.

PCM operates in a continuous cycle, offering cooling effects while also attempting to regulate the body's temperature.

Cooling technologies are applied differently depending on the industry. In apparel, dynamic wicking is the dominant form of cooling technology, primarily because PE yarns tend to be less comfortable on the skin and harder to handle. However, as experts improve their methods, Ross predicts that temperature-regulating options might become more prevalent in clothing in the future, as technologists advance their work in this area.

When it comes to home textiles, a variety of cooling solutions are available. For instance, the Tranquility brand offers both temperature-regulating and cool-to-the-touch weighted blankets. Mattresses and pillows also incorporate various types of cooling features. While marketing terms may differ, each mattress generally includes either a wicking fabric, PE yarn that feels cool to the touch, or a type of phase change material (PCM).

So, Do These Really Work?

Can these cooling products truly keep you comfortable while working out or sleeping at night? Ideally, they should. However, one element that can impact how effective they are is the number of layers between you and the cooling fabric.

For instance, even if you have a cooling mattress, adding multiple layers of non-cooling materials on top might diminish the benefits. Additionally, consider the two sides of your body — the side touching the mattress and the side facing up. The mattress may be cool, but if the blanket on top isn’t, your overall coolness could be compromised.

The microclimate encompasses both the surface you lie on and the materials covering you, Ross explains. A top sheet might trap the heat your body radiates, creating a warm microclimate, while a cool blanket cools the top surface, aiding in heat reduction. The same principle applies to wicking clothes during physical activity.

The great news is that cooling fabrics continue to work as long as you're using them, because they are specifically designed to activate when your body generates heat or humidity.

"It doesn't dissipate or go away," Ross says about temperature regulation technology. "It's activated by your body."

Wicking technology remains inactive until it encounters heat, at which point it starts transferring moisture. It's a bit like the classic thought experiment about a tree falling in a forest: these technologies only activate when they can detect and respond to your body heat.