Let's talk about sweat. The body's natural cooling process can also be its greatest obstacle to comfort when you're wearing the wrong fabric. Much has been made of wicking in the fabric world over the last several years, but wicking isn't always the answer. Different conditions and activities call for different approaches. Through the Science of Fabric, we unlocked a new evaporative cooling technology that optimizes sweat moisture for unparalleled performance in hot weather.

But when wicking is the answer — during high-intensity activity in cold conditions where lingering sweat can cause serious problems — we also offer the most efficient mechanical wicking technology to keep wearers warm and dry.

The Polartec® Delta™ and Polartec® Power Dry® fabric platforms embody these complementary solutions for sweat management. To ensure you'll stay warm, dry, cool, and safe no matter the perspiration situation, you need both of these fabrics in your closet. Keep reading to learn how each platform works, why they're ideal for their intended purposes, and who's taken these technologies to their highest potential in lightweight, performance shirts.

Traditional warm weather workout shirts like the classic cotton t-shirt quickly saturate with sweat, resulting in a soggy, clingy top that won't breathe. Even worse, some "cooling" fabrics rely on chemical treatments to trigger temporary sensory cooling that wash out over the life of the garment. That's money down the drain.

Enter Polartec® Delta™, a true cooling fabric with a precise yarn selection and orientation to go beyond sensory cooling and optimize the body's natural cooling process. This platform's simple yet breakthrough design uses scientific principles to provide metabolic cooling that actually lowers your core temperature, saving energy otherwise lost through excess sweating.

Most Delta styles use hydrophilic Tencel Lyocell fibers knit in a visible radiator pattern around hydrophobic polyester, creating little cones or "volcanoes" that funnel moisture through. As you perspire, the hydrophilic fibers absorb and hold perspiration, while the hydrophobic polyester repels it to maintain highly breathable space between the cones.

The result is akin to a swamp cooler — moisture is held close to the body, with plenty of airflow around it. A recent evolution of the Delta platform hides this advanced tech in a classic piqué construction, ideal for casual collared looks, that functions similarly without the noticeable radiator pattern.

Polartec Delta is the ultimate fabric to maximize the cooling effects of sweat in hot conditions. This cooling technology intentionally reacts differently to sweat than wicking fabrics. Instead of wicking and drying perspiration so fast your body doesn't actually benefit from sweat, Delta fabric masterfully channels perspiration to optimize the body's natural cooling process.

Fox's Flexair Delta Short Sleeve Jersey keeps mountain bikers motivated to hit the trail on the hot, humid dog days of summer. The jersey's contouring fit with four-way stretch ensures maximum mobility while putting Delta's radiator knit technology next-to-skin to do what it does best. Learn more about this and many more of our favorite Delta performance tops in our supplementary Best of Polartec® Delta™ list.

In stark contrast to Delta cooling technology that's engineered to retain some sweat moisture, Polartec® Power Dry® is the most effective fabric for keeping dry when you sweat. Where Delta is perfect for hot conditions, lingering sweat can cause serious problems in the cold. Power Dry's efficient wicking and drying make it a more versatile design solution for all conditions, from hot weather shirting to cold weather base layers.

In the spirit of design versatility, Power Dry comes in styles that look like cotton, so you can have a casual t-shirt with mechanical wicking technology for the ultimate, go-anywhere, do-anything shirt. For winter wicking, Power Dry base layers are a great investment for cold weather comfort in any activity. Power Dry is a powerful addition to your wardrobe to stay warm, dry, and comfortable year-round.

Power Dry once again leverages Polartec's expert yarn selection and orientation for best-in-class moisture management. The bi-component knit construction produces a mechanical wicking effect by placing hydrophobic and hydrophilic fibers where they work most effectively.

The interior surface uses the hydrophilic fibers to pull sweat moisture off the skin and transfer it to the outer layer. The exterior surface's hydrophobic fibers quickly disperse that moisture, increasing its surface area for faster dry times. Continuous evaporation prevents saturation and regulates temperature in both hot and cold conditions.

The Moench Light shirt from Mammut provides a prime example of how Power Dry's mechanical-wicking use cases complement Delta's cooling capabilities. Power Dry keeps your core warm and comfortable with efficient wicking and drying, reducing the chilling effects of lingering sweat as you're cruising the mountain. See more mechanical wicking garments in the Best of Polartec® Power Dry® list .

Sometimes staying dry is the key to staying comfortable; sometimes the key is making the most of moisture. Polartec works hard to stay at the cutting edge of fabric technology and has spent years working to provide solutions for either case. With Delta and Power Dry, we've found complementary solutions for managing sweat in both hot and cold weather conditions, so that you or your customers can go the extra mile.