Zpacks Octa Fleece Thermal Bottoms

Zpacks Octa Fleece Thermal Bottoms - View 3

Zpacks Octa Fleece Thermal Bottoms - View 4

Zpacks Octa Fleece Thermal Bottoms - View 5

Zpacks Octa Fleece Thermal Bottoms - View 6

$67.97 ~~$99.95~~ In stock

Zpacks Octa® Fleece Thermal Bottoms beat the warmth and weight of all other long underwear in their class. Designed to be worn under your hiking pants in frigid weather, under shorts in cool weather, or worn as an ultralight sleep layer, these leggings are unmatched when ounces count.

Octa® Fleece features a soft, fluffy interior that traps warmth and keeps you cozy, and an abrasion-resistant exterior that withstands wear and tear.

Check out the rest of our Octa® Fleece Collection here.

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Standard Shipping: Handling (business days) 0–1; Transit (business days) 7–15.

Express Shipping: Handling (business days) 0–1; Transit (business days) 7–15.

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Standard Shipping · United States: $0.00

Express Shipping · United States: $3.99

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United States · Return window (days after delivery): 30. Return method: By mail. Return postage: Seller pays.

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Customer Reviews (4.6 / 5 · 5 reviews)

Eva E. ★★★★★ Oct 20, 2026

The insulation is surprisingly effective for the weight; I wore them under shorts on a chilly morning hike and stayed perfectly warm. They pack down so small it's almost unbelievable for something this warm. Exactly what I needed for keeping legs comfortable without adding bulk under my pants.

Brian E. ★★★★★ Oct 19, 2026

Paired these with my hiking pants on a freezing morning hike and stayed perfectly warm without feeling bulky. The fleece fabric is lighter than my old wool base layers while providing excellent insulation. Great for cutting weight in the pack without sacrificing warmth.

Elizabeth ★★★★★ Oct 14, 2026

Wore these under my hiking pants on a 20-degree morning and my legs never got cold once. They pack down to nothing in my bag and I barely notice the weight. Best long underwear I've owned for winter trips.