• Laetts Men’s Heavy+ Outdoor Socks in light gray with navy stripes, over-the-calf height, featuring a plush Merino wool blend with HygroHeat™ thermal technology for maximum warmth in extreme cold.
  • Laetts Men’s Heavy+ Outdoor Socks in heather gray with navy stripes, over-the-calf (OTC) height, made with Merino wool and patented HygroHeat™ technology for maximum warmth in extreme cold.
  • Close-up texture detail of Laetts Men’s Heavy+ Outdoor Socks showing cream and navy stripe knit, highlighting Merino wool fibers and patented HygroHeat™ thermal technology.
  • Laetts Women’s Heavy+ Outdoor Socks, over-the-calf height, shown in a 3D standing view with cream and navy stripes, featuring HygroHeat™ patented thermal technology and Merino wool blend for maximum warmth — the warmest socks in the Laetts line.
  • Laetts Women’s Heavy+ Outdoor Socks laid flat, cream with navy stripes, over-the-calf design featuring Merino wool blend and HygroHeat™ patented thermal technology — the warmest socks in the Laetts line.
  • Close-up texture detail of Laetts Women’s Heavy+ Outdoor Socks in cream and navy stripes, showing the plush Merino wool knit enhanced with HygroHeat™ thermal technology for maximum warmth.

Heavyweight+ Outdoor — Full Cushion

Heavyweight+ Outdoor — Full Cushion

Merino Thermal Socks — Warmth Without Bulk

$45.95
$45.95
SAVE Sold out

Patented HygroHeat™

Extra Fine Merino Wool

30 Day Return

Free-shipping on Orders $89.00+

Empowered by the Laetts Merino Thermal System™, this Heavyweight+ Outdoor sock with Full Cushion construction is built for maximum insulation in extreme cold. A dense Merino and HygroHeat™ blend delivers powerful, self-sustaining warmth and active moisture control, while full-foot terry with extended loops creates high loft to blunt cold-ground bite and ease long, static stands in boots or waders.

Engineered for prolonged low-movement use, a stable, resilient knit resists sag and compression when wet, while reinforced heel and toe zones enhance durability. Ideal for ice fishing, winter hunting, and other severe conditions, Heavyweight+ is Laetts’ heaviest construction, designed for situations where thermal mass matters most.

Learn more: Merino Thermal System

Attributes

Shaft Height:    Over-the-Calf

Weight:            Heavy+

Cushion：        Full-cushion strong

Form：             Anatomic

Style：             Sporty

Item Number：L202407

Fibre Content

48% Nylon, 31% Polyester, 19% Wool, 2% Spandex

Care

Machine wash in warm water on gentle cycle, inside out. Do not bleach. Tumble dry low or hang dry. Do not dry clean. Do not iron.

Laetts Men’s Heavy+ Outdoor Socks in light gray with navy stripes, over-the-calf height, featuring a plush Merino wool blend with HygroHeat™ thermal technology for maximum warmth in extreme cold.

Heavyweight+ Outdoor — Full Cushion

$45.95
$45.95
SAVE Sold out
View full details

MERINO THERMAL SYSTEM™

HYGROGHEAT™

BOOTGLIDE™

Warm & Light

Temperature-Regulating

Moisture-Wicking

Odor-Free Comfort

MERINO THERMAL SYSTEM™

HYGROGHEAT™

BOOTGLIDE™

Warm & Light

Temperature-Regulating

Moisture-Wicking

Odor-Free Comfort

MERINO THERMAL SYSTEM™

HYGROGHEAT™

BOOTGLIDE™

Warm & Light

Temperature-Regulating

Moisture-Wicking

Odor-Free Comfort

MERINO THERMAL SYSTEM™

HYGROGHEAT™

BOOTGLIDE™

Warm & Light

Temperature-Regulating

Moisture-Wicking

Odor-Free Comfort

Functions

  • HygroHeat™ Thermal Core

    Patented ceramic system reflects body heat using far-infrared (FIR) technology for self-sustaining warmth — without batteries or bulk.

  • Up to 8.8°C Warmer

    Lab-tested to retain significantly more warmth than standard Merino socks — for longer comfort in the cold.

  • Eco-Friendly Merino Blend

    Made with sustainably sourced Merino wool and performance yarns — soft on skin, lighter on the planet.

  • Moisture-Regulating

    Engineered fibers actively manage sweat and moisture to keep feet dry and comfortable—even under sustained pressure.

  • Natural Odor Control

    Merino’s natural antimicrobial properties help reduce odor — for fresher feet on long days.

    Advanced Technology for Unmatched Warmth & Comfort

    How HygroHeat™ Works

    •  Patented Thermal System
      HygroHeat™ is Laetts’ patented thermal technology that generates warmth through ceramic particles embedded directly into the sock structure.

    • FIR-Emitting Ceramics & Reflective Design
      These particles emit far-infrared rays (FIR) to support circulation and thermal
      retention during activity. The visible white line on the sock is woven with
      reflective yarns that return body heat inward—no batteries, no external power.

    • Performance Warmth, Up to 8.8°C Warmer
      Lab-tested to retain heat better than leading ski sock brands, Laetts’
      HygroHeat™ keeps feet up to 8.8°C warmer.

    • Lightweight Comfort Without Bulk
      All the warmth—without heavy layers. Designed to maintain comfort across changing activity levels while preserving fit precision and mobility.

    Learn more: HygroHeat Technology