Temperature-Regulating Sleepwear - Science or Marketing?

So many sleepwear brands now claim their fabrics are "temperature-regulating" and I wanted to investigate whether this is real science or just marketing.

Brands Making This Claim

• Lunya (washable silk): Claims silk naturally regulates body temp
• Cozy Earth (bamboo): Claims bamboo is 3 degrees cooler than cotton
• Sheex (performance fabric): Uses actual athletic fabric technology
• Under Armour Recover ($100): Infused with minerals that "return infrared energy"

What the Science Says

Natural fibers like silk and bamboo do have genuine moisture-wicking properties. When sweat evaporates through breathable fabric, it cools you. This is real, measurable thermodynamics.

Performance fabrics like Sheex use woven synthetic microfibers that transfer heat away from skin. This is also legitimate technology used in athletic wear.

The mineral-infused claims (Under Armour Recover, etc.) are more dubious. Some studies show marginal benefits but the evidence is thin.

My Testing

I wore each for a week with a sleep tracker monitoring my restlessness. The silk (Lunya) and bamboo (Cozy Earth) both reduced my nighttime wake-ups compared to cotton. The Sheex felt cool but made me sweat more. The UA Recover felt like regular polyester.

Verdict: Natural fiber temperature regulation is real. Synthetic claims are mostly marketing. Stick with silk or bamboo.