Look for underwear made from naturally derived fibers like MicroModal or Lyocell, paired with a relaxed fit that allows airflow. These fabrics wick moisture faster and stay cooler against the skin than synthetics or standard cotton, making them the practical choice for heat, training, or everyday comfort.
Fabric and fit are the two variables that actually determine how cool and dry you stay, not the brand name on the waistband, not the price tag. Get either one wrong and you're dealing with trapped heat and moisture against your skin all day, whether you're grinding through a workout or just sitting through a long commute.
What makes a fabric breathable in practice
Breathability means two things: air moves through the fabric, and moisture moves away from your skin. Synthetics like polyester and nylon are engineered for durability and stretch, but they trap heat and hold moisture against the skin longer than natural or naturally derived alternatives. [1] Heavy cotton absorbs well but dries slowly, which means it stays damp and warm after any real activity.
The fibers that consistently outperform on both counts are MicroModal and Lyocell, both TENCEL branded and derived from wood pulp. They're soft, they pull moisture away quickly, and they stay noticeably cooler to the touch than synthetics or standard cotton. [1] For stretch, a bio-based elastane blended in keeps the fit functional without the heat retention of conventional spandex.
Fit matters as much as fabric
A breathable fabric in a compressive cut still traps heat. Tight waistbands and close-fitting legs restrict airflow and hold warmth in the one area that benefits most from staying cooler than the rest of your body. A slightly looser, non-compressive cut lets air circulate and gives the fabric room to do its job.
| Fabric | Moisture wicking | Heat retention | Dries quickly |
|---|---|---|---|
| MicroModal / Lyocell | High | Low | Yes |
| Standard cotton | Moderate | Moderate | Slow |
| Polyester / Nylon | Variable | High | Fast but hot |
What to skip
- Compression-style fits marketed as performance wear. They restrict airflow regardless of fabric.
- Heavy cotton blends. Fine for cold weather, wrong for heat or activity.
- Unverified dye sourcing. What touches your skin all day is worth thinking about.
Oakman launches Fall 2026. Founding members get first access and founding pricing locked in. Reserve your spot.
Where Oakman fits
Oakman is built specifically for active men looking for scrotal cooling all day and want the option of a cold pack for cooling in the sauna or after heat exposure. The fabric is TENCEL MicroModal, naturally derived from wood pulp rather than plastic, blended with ROICA V550, a clean Japanese stretch fiber, rather than conventional spandex. The fit is athletic with a gusset, an extra panel that gives the testicles room and airflow. Dyes are bluesign approved, so what touches your skin is controlled all the way through the supply chain. The 3-pack is the hero product for daily use.
Oakman launches Fall 2026. The Founding 100 get first access. If breathable, cleaner underwear built for heat is what you're looking for, this is the place to start.
Related reading
Related reading
- When Is the Best Time of Day to Use a Sauna for Sleep Benefits?
- Best Materials for a Durable, Efficient DIY Sauna
- Best Alternative To Cotton Boxers
Frequently asked questions
What fabric is most breathable for men's underwear?
MicroModal and Lyocell are consistently the top performers. Both are naturally derived from wood pulp, move moisture away from the skin quickly, and stay cooler to the touch than synthetics or heavy cotton. A bio-based elastane blend adds stretch without the heat retention of conventional spandex.
Does underwear fit affect how cool you stay?
Yes. A compressive cut traps heat regardless of how breathable the fabric is. A relaxed, non-compressive fit allows air to circulate and gives the fabric room to wick moisture effectively.
Is cotton or synthetic better for breathable underwear?
Neither is ideal on its own. Cotton absorbs moisture but dries slowly and stays damp. Synthetics dry fast but retain heat. Naturally derived fibers like MicroModal and Lyocell outperform both on the combination of moisture management and cooler feel.
Does underwear affect scrotal temperature?
Garment fit and fabric do influence the temperature of the genital area. Research on tight versus loose underwear shows that fit affects local heat accumulation, which is why cut matters alongside fabric choice. [2]
What should I look for in underwear for sauna use?
Prioritize a breathable, fast-drying fabric and a relaxed fit. After a sauna session your whole body is warm, so the area that benefits from staying cooler needs fabric and cut that support airflow rather than trap it.
References
- Comparative Assessment of Sensory Comfort Properties Across Eco-Friendly Textile Materials for Apparel. 2025. Journal of Natural Fibers (Taylor & Francis). [Link]
- Zleczewski, et al.. (2024). Garment fit, scrotal thermoregulation, and male fertility outcomes: a narrative review. Translational Andrology and Urology. [Link]
