Changing seasons mean changing temperatures, and that's true of both inside and outside your home. While you can't control the elements beyond your fall walls, thermal curtains can help you maintain a cozy (or cool) environment indoors. These home décor pieces look and are hung like typical curtains, but were ultimately designed to provide insulation. From colorful and neutral iterations to built-in technology that blocks out the sun, the options you'll see ahead were culled by interior designers and curtain experts alike; they shared their favorite thermal curtains on the market. Keep reading to learn how thermal curtains work, why consumers should consider purchasing these window treatments for their homes, and the best options to shop right now.

Related: 10 Stylish Blackout Curtains That Will Upgrade Your Home—and Your Naps

To understand how thermal curtains work, it's helpful to think about how you dress to keep warm during chilly winter weather: You layer articles of clothing. "Thermal curtains work the same way, but in our homes," explains a community manager at the Plumbing Lab. "Curtains are layered to trap air in between the pieces of fabric, creating a barrier of hot air that leads to insulation." While hung over a window, this "air pocket" and layered fabric "reduces thermal transference," says Angela Boswell, the co-founder of The Drape. "This means that the temperature on one side of the window panel will not have an effect on the temperature on the other side of the window panel." Even if you can see snow outside, thermal curtains keep your space cozy.

When shopping for thermal curtains, you should prioritize certain materials—not the brand. All thermal insulated curtains are made from heavy, thick textiles such as cotton and polyester, explains Marco Bizzley, certified interior designer and consultant at HouseGrail: "This prevents air from coming in or escaping through your window." Not all of these window treatments, however, were created equal—but paying attention to the thickness of the fabric can help ensure a successful purchase. "The thicker and more dense the window curtain fabric, the less transference," says Boswell. "Thermal window panels should be composed of tightly woven fabrics and have more than one layer." If you're shopping for curtains in person, Boswell suggests examining the fabric through your cell phone camera to check if it is densely woven. "If no light, or minimal light comes through on your screen, then that is a tight weave that will have thermal properties," she explains.

While thermal curtains are often utilized during winter months, they are just as helpful in the summer. "Essentially, they'll keep heat where you want it—either inside or out," says Michelle Keldgord, a home designer. During warmer seasons, Keldgord adds, "You can keep the heat trapped between the window and the curtain, leaving your home impressively cooler." Thermal curtains won't only make you feel good because of their temperature-regulating properties: They can also save you money. "Consumers benefit from them because they can help lower their heating and cooling bills," says Bizzley. "Since the curtains prevent air from coming in or escaping, the heater and air conditioner won't have to work as hard." Best of all, these pieces are available in a wide array of colors, sizes, and styles—which is much more aesthetically pleasing than other weatherproofing methods like plastic window insulation, remarks Boswell.

Related: The Best Simple Linen Curtains for Your Neutral Home

Since the best thermal curtains are thick and tightly woven, they also feature room darkening properties, which means they often double as blackout iterations. "These are some of my favorites," says Bizzley of this Nicetown set. "Along with the insulating layer, there is additional brown cloth that not only keeps the air in, but the light out." Moreover, these curtains include another layer that filters particles in the air to improve your home's air quality and cleanliness.

Shop Now: Nicetown Four-Layer Thermal Blackout Curtains, $85.50, nicetown.com.

Bizzley also recommends this pair. "I love this curtain—it's made from 100-percent polyester," he says, "and its weighted hem keeps the curtain thick enough to prevent warm air from escaping."

Shop Now: HPD Thermal Room Darkening Curtain, $38.24, amazon.com.

Thermal curtains can have function and form. Keldgord recommends this set; it keeps your space dark and is available in "several great color and size options to suit any style."

Shop Now: Sun Zero Barrow Energy Efficient Rod Pocket Curtain, $17.57, amazon.com.

Want a little peace and quiet to go with your warmer space? Certain thermal curtains also feature noise-reducing technology. "For those sick and tired of noise coming in from the outside world, these are an excellent choice," Keldgord says.

Shop Now: MIUCO Two Panels Room Darkening Thermal Insulated Grommet, $19.99, amazon.com.

"The first thing I like about Moondream's curtains is that they were produced without any harmful chemicals," Bizzley explains. "It's made from 99.7-percent polyester and has a thermal insulated lining to prevent air from coming in or out."

Shop Now: Moondream Thermal & Blackout Curtain, $59, moondreamwebstore.com.

These are a "clear winner" for shorter windows, notes Keldgord. And if you think neutral colors fit better into your home décor style, look no further than these pieces.

Shop Now: BGment Blackout Curtains for Bedroom, $16.76, amazon.com.