Hemp vs Cotton: A Comparison Guide for Hot Weather

The mercury hits 95°F as you reach mile seven of your hike through Big Bend National Park. Your shirt clings to your back like a desperate ex, and that refreshing breeze you're praying for feels more like a hair dryer to the face. In this moment, the fabric between your skin and the merciless sun isn't just clothing—it's survival gear.

The Fabric Fight We're Not Having (But Should Be)

For decades, cotton has dominated our closets with the quiet confidence of an incumbent politician. It's familiar, comfortable, and boasts an impressive PR campaign ("The fabric of our lives," anyone?). Meanwhile, hemp—despite its 10,000-year résumé as one of humanity's most versatile plants—remains the underdog in your adventure wardrobe.

Let's cut through the marketing noise and lay bare what science tells us about these two contenders when the thermometer starts to misbehave.

Cotton's Comfort Zone: A Love Letter to the Moderate

Let's give cotton its due: below 80°F, it's nearly perfect. Soft, breathable, and with excellent drape, cotton feels fantastic against the skin in mild conditions. It absorbs moisture well (up to 27% of its weight without feeling wet), and its natural fibers allow for decent air circulation when the humidity plays nice.

Cotton shines during crisp mornings in Acadia, or perfect fall days in the Great Smoky Mountains. There's a reason why it accounts for 75% of all natural fiber production worldwide—it's genuinely pleasant when conditions are forgiving.

When Cotton Becomes the Enemy: The 90°F Tipping Point

Here's where things get uncomfortable—literally. Once temperatures climb past 90°F, cotton's legendary moisture absorption becomes its fatal flaw. That 27% water retention ability? It's now your worst enemy.

When cotton gets wet (whether from sweat or rain), its insulating properties increase by 40-60%. Yes, you read that correctly—wet cotton actively makes you hotter by trapping heat next to your skin while simultaneously feeling heavier and more restrictive. The evaporative cooling effect that should be helping you is instead working against you, creating what wilderness experts call a "microclimate sauna" between fabric and skin.

In desert environments, this means your body works overtime for thermoregulation. In humid conditions? It's even worse, as your sweat has nowhere to evaporate. This isn't just uncomfortable—it's potentially dangerous, leading to heat exhaustion or worse.

Hemp: The Heat-Defying Alternative

Enter hemp, the ancient fiber making a modern comeback. Here's what the evidence shows about its performance when temperatures soar:

• Hemp fabrics provide 98% UV protection compared to cotton's 73%, meaning less radiant heat reaches your skin
• Hemp wicks moisture away from the body 30% faster than cotton
  
• Hemp fibers are naturally hollow, creating superior breathability (similar to how double-walled tumblers outperform single-wall versions)
• Hemp's thermal conductivity is 30-35% better than cotton, allowing body heat to escape more efficiently

These aren't marginal differences—they represent significant advantages when every degree matters.

The Tale of Two Climates: How Hemp Excels Everywhere

In arid heat (think Joshua Tree or Canyonlands, or urban areas like Phoenix and LA in the summer), hemp's porous structure creates natural ventilation channels that cotton can't match. The hollow fibers pull sweat away from your skin and distribute it across a larger surface area, accelerating evaporation by up to 30%. This creates a natural cooling effect similar to how traditional desert cultures have stayed comfortable for centuries.

In humid conditions (Everglades, Congaree or urban areas like NYC and DC in the summer), hemp's antimicrobial properties prevent the growth of odor-causing bacteria—bacteria that thrive in cotton's persistently damp environment. Hemp also dries approximately 3-4 times faster than cotton when both are saturated, meaning you spend less time feeling like you're wearing a wet blanket on your Appalachian Trail section hike.

The Sustainability Bonus You Didn't Know You Needed

While performance remains our primary concern, it's worth noting that hemp requires 50% less water than cotton to grow and naturally resists pests without pesticides. Hemp clothing typically lasts at least 5 times longer than comparable cotton garments before showing signs of wear.

This isn't just environmental virtue signaling—it's practical economics. When you're dropping serious cash on adventure gear, longevity matters. A hemp shirt that survives over 50 high-intensity outings costs less per adventure than a cotton one that deteriorates after 10.

The Bottom Line: Right Tool, Right Temperature

The most prepared adventurers don't pledge blind allegiance to any single material. They strategically deploy fabrics based on conditions:

• Temperatures under 80°F with low exertion: Cotton can shine
• Temperatures between 80ºF and 90ºF: Cotton is acceptable, but you’ll probably be more comfortable in high-quality hemp
• Anything over 90°F or high-exertion activities: Hemp becomes the obvious choice
  

Adventuring in extreme conditions isn't about looking good in Instagram photos (though hemp's natural wrinkle resistance helps there too). It's about adapting to adversity with intelligence and grit—precisely the values that drive our approach to the outdoors.

Whether you're tackling the scorching trails of Zion or bushwhacking through the humid undergrowth of the Everglades, the right fabric isn't just a comfort choice—it's a performance decision with real consequences.

Choose wisely. Your adventure depends on it.

~ Doug

Interested in seeing our collection of performance hemp adventure wear? Check out our National Parks Collection, designed specifically for extreme temperature management, at the link in our bio.