Heavy Insulation

Warmth You Can Bet Your Summit On

When the temperature drops and the wind starts to bite, your insulation becomes more than comfort — it’s survival. This collection features heavy down and synthetic parkas trusted by guides for Denali, Aconcagua, and other big, cold mountains. Built for warmth, durability, and reliable loft in brutal conditions, these pieces are designed for life above freezing.

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Mountain Hardwear

Phantom Belay Down Parka

$640.00 USD

Mountain Hardwear

Women's Phantom Belay Down Parka

$640.00 USD

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Your Buying Guide For

Heavy Insulation

Big mountains demand big insulation. Understanding how fill ratings, materials, and design affect warmth helps you choose the right jacket for your next climb. Here’s what to know before you zip up.

Still have questions? Feel free to reach out!

What do down fill ratings mean?

Fill power measures how much space one ounce of down occupies. Higher numbers like 800 or 900 mean the down is loftier and traps more air for its weight, giving better warmth-to-weight performance. Lower fill power (like 600) can still be warm but may require more down and result in a bulkier jacket.

What’s the difference between down and synthetic insulation?

Down offers the best warmth-to-weight ratio and compressibility but loses performance when wet. Synthetic insulation, like PrimaLoft or Coreloft, stays warm even in damp conditions and dries faster. For cold, dry expeditions, go down. For mixed weather or humid conditions, synthetic is often the better call.

Do I need an expedition parka or just a warm midlayer?

Expedition parkas are built for sub-zero temperatures and extended exposure, not casual use. If you’re climbing cold, high peaks or standing still for long periods, a heavy parka is essential. For most summer alpine climbs, a midweight down or synthetic jacket is plenty.