Insulated clothing traps warm air around the body, making it useful during cold hikes, travel, camping and rest stops. Down offers excellent warmth for its weight, while synthetic insulation is often easier to manage in damp or changeable conditions.

Compare insulation type, fill power where relevant, total insulation amount when listed, construction, packability, weather resistance and intended activity. Active insulation should release heat during movement; belay-style or everyday insulation usually prioritizes warmth.

Down fill power measures loft efficiency, while synthetic insulation is often described by construction or grams per square meter. Neither number alone gives a complete temperature rating. Wind, humidity, activity, layering and personal cold tolerance all influence warmth.