December 12, 2025 Reading time: 9 minutes
Man waiting in the snow for the tram, wearing an extremely warm 850 GSM hoodie

Warm winter hoodies: Why 850 GSM can replace your winter jacket

Winter in Switzerland: The hoodie stress test

It's 7 a.m. in Zurich. You're waiting for the tram. The thermometer reads 2 degrees Celsius, and there's a biting wind. You're wearing your favorite designer hoodie under a denim jacket. And you're freezing. The wind whistles through the fabric as if it weren't even there.

Many people believe hoodies simply aren't made for real winter. That's wrong. A hoodie CAN replace a jacket, but not with the standard specs you'd find in a sports store. If the material is right, the hoodie becomes armor against the cold. We're talking about warm winter hoodies that truly deserve the name.

Why you're cold: The GSM lie

Most hoodies marketed as "warm" are a rip-off. Major sportswear brands often use fabric weights between 280 and 320 GSM (grams per square meter). That's fine for the gym or spring, but this material fails in single-digit temperatures. It simply doesn't have enough mass to retain heat.

You can't cheat physics: mass stores energy (heat). Our solution is the "GSM Monster": 850 GSM . That's almost three times the density of standard fabric. When you touch this material, you'll feel the difference immediately. It's a barrier, not a T-shirt fabric.

Double layered against the wind

Besides weight, the construction is crucial. Single-layer fabrics allow wind to pass through. Our double-layer construction acts like insulated glazing.

Two layers of high-density cotton blend are sewn together. A minimal air cushion forms between them. This insulating layer of air provides the best protection possible. The wind hits the first layer, is slowed down, and doesn't reach your skin. The result: You stay warm, even in a draft.

Macro shot of the heavy 850 GSM fabric in winter
Winter hoodie with Matterhorn design in dark blue

Winter hoodie "To the Matterhorn" (850 GSM)

Designed for temperatures down to -15°C (in layering). Double-layered construction, 850 GSM weight, and wind-resistant. Your replacement for a transitional jacket.

  • Construction: Double-layered
  • GSM: 850 (Ultra Heavyweight)
  • Use: Winter & cold transitional seasons
  • Price: CHF 112.00
For the winter upgrade

The temperature guide: When should I wear what?

An 850 GSM hoodie is a versatile tool. Here's our recommendation for everyday Swiss life:

  • +10°C to +5°C (transitional): Hoodie only. A T-shirt underneath is perfectly sufficient. Jacket? Unnecessary.
  • +5°C to -5°C (Cold): Hoodie + Base Layer. This is where the first layer comes into play. This combination will keep you warm as long as you're active.
  • -5°C to -15°C (freezing cold): Base layer + hoodie + shell/coat. The hoodie now functions as an extremely effective mid-layer. It retains warmth, while the coat protects against snow and moisture.

The perfect layering system

The thickest hoodie is useless if you sweat and get cold underneath it. The first layer against your skin (base layer) is crucial. Synthetic materials can quickly develop odors, and wool can be itchy.

We recommend a long-sleeved base layer shirt made of 100% cotton . It's ultra-soft against the skin, wicks away moisture, and forms the foundation for thermal insulation. It closes the gaps at the wrists and neck, where cold air often penetrates.

Flatlay with base layer shirt and heavy hoodie
Base layer long-sleeved shirt, cotton

Base layer long-sleeved shirt (100% cotton)

The perfect base layer. Ultra-soft on the skin, it retains body heat under the hoodie.

  • Material: 100% cotton
  • Fit: Slim / Regular
  • Function: Heat base
  • Price: CHF 11.95
To the Base Layer

Frequently Asked Questions

Does a hoodie really replace a winter jacket?

Yes, down to about +5°C the "Zum Matterhorn" (850 GSM) works superbly as a standalone outer layer. It blocks wind and retains heat better than many lightweight transitional jackets. In sub-zero temperatures, it serves as an extremely warm mid-layer under a coat.

How do I wash an 850 GSM?

Due to its weight, a gentle wash cycle at 30 degrees is mandatory. Important: Do not hang to dry, as the weight could distort the fabric when wet. Always dry flat.

Will it fit under a coat?

Yes, but the coat shouldn't be "slim fit". The hoodie has volume. However, under a loose-fitting wool coat or parka, the structured hood looks extremely good and offers maximum protection against the cold.

Conclusion: Prepare yourself for the cold

Winter is too long to freeze. Invest in gear made for the elements. With 850 GSM and proper layering, the cold becomes irrelevant.

From the Gradualbasics team

This guide is based on our experiences in the Swiss winter. We test our hoodies where it counts: outdoors in the cold, not in a laboratory.

Back to blog

Leave a comment