Zpacks Octa Fleece Hoody vs Thermal Bottoms: Layering System

Quick answer

For a balanced ultralight layering system, pair the Zpacks Octa Fleece Hoody for your core and the Thermal Bottoms for your legs. Choose the Hoody if you need one piece for variable conditions; choose the Bottoms if your legs get cold first.

Trade-offs at a glance

• Zpacks Octa Fleece Hoody: Covers torso, arms, and head; full zip for venting. Best for variable conditions where you need to adjust warmth quickly. Ideal as a primary midlayer or standalone piece for cool to cold weather.
• Zpacks Octa Fleece Thermal Bottoms: Covers legs; can be worn under pants, under shorts, or as a sleep layer. Best for targeted leg warmth without adding a heavy base layer. Great for extending your sleep system's warmth or for cold starts on the trail.
• Combined system: Wearing both pieces creates a cohesive Octa Fleece layering system that keeps your core and legs warm while remaining ultralight. Pair with a wind or rain shell to lock in warmth and block wind.

Product facts

• Zpacks Octa Fleece Thermal Bottoms: Zpacks Octa® Fleece Thermal Bottoms beat the warmth and weight of all other long underwear in their class. You can add significant leg warmth without the bulk or weight penalty of traditional thermal bottoms.

  

• Women's Octa Fleece Hoody - Full Zip: The Women's Full Zip Octa Fleece Hoody is built with advanced Octa® fleece for an unbeatable balance of durability, breathability, and warmth. The full zip lets you dump heat quickly during high-output climbs while still keeping your core warm at camp.

  

Which one fits your hike?

Best for

• Hikers who want one versatile piece for torso warmth and easy venting – choose the Hoody
• Hikers whose legs get cold first or who want a dedicated sleep layer – choose the Thermal Bottoms

Not for

• Hikers who need a full-body insulation layer from a single garment – you’ll want both pieces
• Hikers who prefer a single heavyweight layer over a modular system – consider a down jacket instead