Thorlo Extreme Cold Maximum Cushion OTC Socks

Color: Light Gray
Notify Me When Available

Thorlo's Extreme Cold Over-the-Calf sock is ideal for keeping warm in sub-zero environments. Thorlo's EXCOU Extreme Cold Over-the-Calf Boot Sock features dense cushioning and mesh vents to keep your feet protected, warm, and dry. Showcasing heavyweight padding at the ankle, ball, heel, and toe, this sock protects and insulates even under the most extreme conditions. Ideal for outdoor use, on the job, or in the field. This is a Unisex sock and identical to the HEOU and ST socks by Thorlo.


  • Unisex sock
  • Over-the-Calf height hits just below the knee
  • Ideal for extremely cold conditions
  • Wicks moisture
  • Heavyweight padding in the heel, ball, and toe
  • Extra protection against blisters, shock, impact, and abrasion
  • Extra 100% wool yarn heel provides added warmth
  • Ventilation panel for moisture control and breathability
  • Favored by Mt. Everest climbers to prevent frostbite
  • Named a "Guides Choice" by the American Alpine Institute
  • Made in the USA

Customer Reviews

Based on 20 reviews

Heavy, well made socks.

W.D. (Brooklyn, NY)
Thorlo Cushioned OTC Socks

These were exactly what I was looking for. For me, they could be thicker at the feet.

S.I. (Columbia, MO)

Thorlo Extreme Cold Maximum Cushion OTC Socks

A. (Solon, IA)
Very warm!

I bought these for a winter campout. I had packed extra socks to have dry feet for the afternoon/evening, but found that I didn’t need the extras! These Thorlos kept my feet warm and dry all day. Plus, they had the same cushioning that I love in their lightweight hiking socks. Love!

S.H. (San Rafael, CA)
Love these socks!

I got a pair of Thorlos years ago during a Canadian winter where temperatures were quite a bit below zero, but then noticed I really enjoyed using them to sleep in back home in the winter because my feet always get so cold. These not only do the trick, but have extra arch support and heel cushioning. Happy with this purchase!