Why Base Layers Are Not Just for Winter

When people hear “thermal underwear,” they usually think snow, frost, and skiing. But in 2025, base layers are part of year-round activewear. Functional, breathable, and lightweight — they’re useful even in mild weather.

During spring, summer, and autumn, base layers don’t insulate — they regulate. Synthetic or bamboo-based fabrics help wick moisture, keeping the body dry during hiking, cycling, and daily activity. They prevent overheating, dry quickly, and provide comfort under backpacks or outerwear.

On camping trips or mountain hikes, they serve as both a base layer and sleepwear. In the summer, a thin thermal tee or long sleeve protects from cold nights and sun exposure without adding bulk.

Key Benefits:

• Maintains stable body temperature
• Wicks moisture effectively
• Reduces odor with antimicrobial properties
• Works under gear and packs
• Keeps its shape after washing

4hz.store features high-performance base layers from Icebreaker, HI-TEC, Trespass, Montane, and Haglöfs — suitable for hiking, running, travel, or everyday wear.

Base layers are not just about heat. They’re about comfort, performance, and freedom in motion.