Dermatologists are sounding the alarm: Choosing the wrong sauna hat material this winter could damage your scalp. With sauna use peaking in colder months, experts break down the wool felt vs. polyester felt debate from a medical perspective.

Wool felt’s natural keratin aligns with human hair proteins, reducing static and friction. “It’s ideal for dry winter scalps,” says Dr. Helena Ross of Oslo Skin Clinic. “The gentle exfoliation from wool fibers can even prevent dandruff.” However, lanolin residues in untreated wool may trigger allergies.

Polyester felt, while hypoallergenic, poses hydration risks. “Synthetics create a ‘greenhouse effect’—heat gets trapped, stripping scalp oils,” warns trichologist Marco Bianchi. His winter tip: Apply aloe vera gel before wearing polyester hats.

A 2023 study in Journal of Thermal Medicine tested both materials in -10°C post-sauna conditions. Wool users retained 30% more scalp moisture, but polyester groups reported fewer itch incidents. “There’s no one-size-fits-all,” concludes Dr. Ross. “Rotate materials based on your skin type.”

Brands like ScalpGuard now offer mixed-fabric kits, while influencers tout “sauna hat skincare routines” with thermal-protectant sprays—a winter wellness niche poised to grow.