Our Commitments
STAY WARM
We all go outside, no matter what the season. We ski, snowboard, hunt, camp, fish, explore. We walk our dogs, commute to work, watch sports, and even party outside on New Year’s. Whatever gets you out there; you want to stay warm. Well you’ve come to the right place! Our gear is made to keep you warm and protected from head to toe. And not just warm enough to grit through it. We mean really warm. Like, surprisingly warm.
COMFORT & FOCUS
We believe in comfort. We use the latest fabrics, the most advanced technologies, and a remarkably unique R&D process that’s delivered new forms of comfort every year since 1978. We create with a function first approach, keeping in mind relevant style trends. We were the first to bring rechargeable heated gloves to market, and we own 19 patents aimed at making your outdoor experience warm and comfortable.
DOING THE RIGHT THING
As a family business we know we’re all in this together, so we take care for not only the environment, but our employees, our partners, our suppliers, and of course our customers as well. Our Community Impact shows some of the amazing institutions we are proud to collaborate with in this industry, all of whom are working tirelessly to preserve and bring the joy of the outdoors to everybody.
At Seirus, sustainability is at the heart of what we do. We’re dedicated to creating products that not only perform well, but also tread lightly on the planet. That’s why we continue to make significant changes to how we make our gear. For starters, we have converted the majority of our fleece to be sourced from recycled plastic bottles, reducing waste and giving new life to old plastics. Our laminations are all done utilizing non-toxic eco friendly adhesives, increasing our ability to build products that are safe for you and the environment. Internally, we’ve taken steps to minimize our footprint too, like ditching plastic polybags in favor of biodegradable ones, reducing our paper usage in fulfillment by 50% and powering our offices with solar energy.
But our commitment to sustainability doesn’t stop there. We’re also tackling tough issues like PFAS, harmful chemicals commonly found in waterproof coatings. We’ve been working on alternatives since 2020 and are proud to say that our latest ECO treatment is not only effective but also completely PFAS-free. So when you choose Seirus, you’re not just getting high-quality gear - you’re also supporting a company that’s leading the way in sustainable solutions.
What Powers Our Base Layers?
Heatwave™ Technology—the ultimate innovation in warmth, built to keep you comfortable no matter how cold it gets.
🔥 Reflective Stage – Reflects your body heat back to you, keeping warmth where you need it.
⚡ Kinetic Stage – Your movement fuels the heat, turning energy into extra warmth.
When combined, it’s like having your own personal heat engine—lightweight, powerful, and always working to keep you warm.



Find Your Perfect Base Layer


Shop Heatwave Base Layers
No matter where your adventures take you, our base layers are designed to keep you comfortable, dry, and ready for anything. Explore our styles to find the perfect fit for your activity and the weather ahead.

All Season
Versatile | Lightweight & Buildable Warmth | All Activities | All Climates

Reflective
Versatile | Midweight Warmth | Medium-Intensity Activities | Colder Climates

Performance
Performance | Max Wicking | Targeted Warmth | Medium to High-Intensity Activities

Winter Weight
Heaviest | Maximum Warmth | Low to Medium-Intensity Activities | Coldest Climates
Shop All
Coreshield™ Storm Layer Jacket
Coreshield™ Storm Layer Jacket
Mens Heatwave™ Performance Base Layer Crew Top
Mens Heatwave™ Performance Base Layer Crew Top
Women's Heatwave™ Performance Base Layer 1-4 Zip Crew Top
Women's Heatwave™ Performance Base Layer 1-4 Zip Crew Top
Men's Heatwave™ Performance Base Layer Bottom
Men's Heatwave™ Performance Base Layer Bottom
Women's Heatwave Performance Base Layer Bottom
Women's Heatwave Performance Base Layer Bottom
Men's Heatwave™ Winter Weight Base Layer Crew Top
Men's Heatwave™ Winter Weight Base Layer Crew Top
Women's Heatwave™ Winter Weight Base Layer Crew Top
Women's Heatwave™ Winter Weight Base Layer Crew Top
Men's Heatwave™ Winter Weight Base Layer Bottom
Men's Heatwave™ Winter Weight Base Layer Bottom
Women's Heatwave™ Winter Weight Base Layer Bottoms
Women's Heatwave™ Winter Weight Base Layer Bottoms
Women's Heatwave™ All Season Base Layer Top
Women's Heatwave™ All Season Base Layer Top
Men's Heatwave™ All Season Base Layer Crew Top
Men's Heatwave™ All Season Base Layer Crew Top
Women's Heatwave™ All Season Base Layer Bottoms
Women's Heatwave™ All Season Base Layer Bottoms
Men's Heatwave™ All Season Base Layer Bottoms
Men's Heatwave™ All Season Base Layer Bottoms
Mens Heatwave™ Performance Base Layer ¼ Zip Mock Neck Top
Mens Heatwave™ Performance Base Layer ¼ Zip Mock Neck Top
Women's Heatwave™ Performance Base Layer ¼ Zip Mock Neck Top
Women's Heatwave™ Performance Base Layer ¼ Zip Mock Neck Top
Mens Heatwave™ Performance Base Layer Quick Hoodie Top
Mens Heatwave™ Performance Base Layer Quick Hoodie Top
Womens Heatwave™ Performance Base Layer Quick Hoodie Top
Womens Heatwave™ Performance Base Layer Quick Hoodie Top
Mens Heatwave™ Reflective Base Layer Top
Mens Heatwave™ Reflective Base Layer Top
Womens Heatwave™ Reflective Base Layer LS Top
Womens Heatwave™ Reflective Base Layer LS Top
Womens Heatwave™ Reflective Base Layer Bottoms
Womens Heatwave™ Reflective Base Layer Bottoms
Mens Heatwave™ Reflective Base Layer Bottoms