Women's thermal fleece is most often made from polyester–spandex blends for stretch and warmth. Common mixes cited include about 90% polyester/10% spandex and 95% polyester/5% spandex, which balance insulation with flexible fit.
Many women's thermals use a soft fleece lining to trap heat while remaining lightweight. Some pieces use textured fleece constructions — for example, a smooth inner face with a grid or textured outer face — to add warmth without bulk.
Thermal bottoms are often ankle-length, while thermal tops typically reach the hip or just below the waist. Common fits reported include fitted (close to the body), straight‑leg or athletic fits for bottoms, and regular or close-fitting tops designed for layering.
Common anti‑bunching features include spandex or 4‑way stretch fabrics for mobility, elastic waistbands on bottoms, tagless construction, and close‑fit openings (e.g., snug cuffs and hems) that help the garment stay put.
Many women's thermals list moisture‑wicking and quick‑drying fabrics or specialized moisture‑wicking fibers designed to pull sweat away from the skin and help wearers stay drier during activity.
Thermal bottoms commonly use a pull‑on closure and rely on elastic waistbands to keep them in place comfortably without excessive squeezing.