Ready for the leaves to start changing.

Ensure solid comfort when you tackle the trail in chilly fall weather with the SmartWool PhD Outdoor Heavy Crew Socks. Designed to fit smoothly into your hiking shoes or boots, these cozy socks keep your feet dry and comfy from the relative warmth of the trailhead to the biting cold of the summit.

Merino wool regulates temperature so your feet don't overheat during arduous uphill stretches or get cold at the campsite. The wool is blended with nylon for enhanced durability, as well as a touch of spandex for movement-conforming stretch. Smartwool's 4 Degree Elite Fit System ensures your socks won't slip or bunch during your trek, and heavy cushioning makes these socks ideal for extended journeys in rugged backcountry terrain.

  • Heavyweight performance for cold weather
  • Soft merino wool regulates temperature
  • Blended with synthetics for stretch and durability
  • Flat knit toe seam relieves pressure points
  • 4 Degree Elite Fit System won't slip or bunch as you walk
  • Heavy cushioning is ideal for long hikes on rugged trails
  • Reviews
  • Q & A

Smartwool PhD Pro Socks

Learn more about the fit, features, and benefits of Smartwool PhD Pro Socks. #gofarfeelgood

Learn More: Smartwool PhD Socks

Learn more about the comfort, fit, and durability of Smartwool PhD performance socks. #gofarfeelgood

Great heavy weight sock!

  • Familiarity: I've put it through the wringer

I love these socks, best mountaineering sock I have ever worn. These socks truly make a difference in my performance on the mountain. Made of Merino Wool, they are very comfortable & durable. Super warm! I've been buying this brand for over 10 years and am still wearing my original pair. Highly recommend !

Nice

    Comfortable

    Go to hiking socks

    • Familiarity: I've put it through the wringer

    Very comfortable socks that are not too hot

    Warm, but not too warm

    • Familiarity: I've used it several times

    I am not a huge sock wearer, but I have to pop some on in the winter. These are awesome for my boots that have no insulation on winter days. They are definitely too warm for me to wear any other time. I assume they are awesome for long distance backpackers and mountaineers. They have lots of cushion and would hold up over miles.

    From Winter Hikes to Pub Crawls

    • Familiarity: I've put it through the wringer

    These socks are extremely warm, I initially got them to walk my dog in the winter..I now wear them under my pants nearly everywhere in the winter. They are the perfect all round winter sock!

    Your Toes Will Love 'Em

    • Familiarity: I've put it through the wringer

    Rotated through two pair during a full season of hiking and climbing in the Cascades.... No complaints! I use these without a liner sock and have had no problems. They don't stretch out and bunch up or slide down during use and don't show much wear on the heel and toes, despite heavy use.

    love these socks!

    • Familiarity: I've put it through the wringer
    • Fit: True to size

    super soft and warm! My go-to ski socks! I have a few pairs and I use them every time I go snowboarding! They're also very durable

    Unanswered Question

    Is socks unisex? Looking for female version of socks.

    Never a blister

    • Familiarity: I've put it through the wringer
    • Fit: True to size

    This is my go-to sock for serious hiking and climbing in boots. I don't use any liner sock. I hiked 13 miles in Glacier National Park one day last summer in Trango S Evos and no blisters or hot spots.

    Extremely warm without being bulky

    • Familiarity: I've used it several times
    • Fit: True to size
    • Size Bought: Large

    I put these socks to the test initially indoors and my feet were actually too warm. This is a very good problem to have. These socks fit very well and they do not slide down as Smartwool claims.

    I wear these in my Northface Chilkat boots and my Bauer Supreme One80 hockey skates. I was pleasenly surprised how well they kept my feet warm. My skates do not provide much insulation but I skated for hours in 20 degree weather with warm feet.

    I highly reccoment these socks. All around good fit and great build quality. Defiantly worth the money. These Smartwool socks deliver extreme comfort due to padded zones on the foot bed. Mostly importantly though, they will keep your feet warm!

    These fir true to size. I am a 9.5 and the Large fit perfectly.

    Smartwool socks are the best!

    • Familiarity: I gave it as a gift but have feedback to share
    • Fit: True to size

    Smartwool socks are some of the best socks you can put on your feet! Super warm, keep your feet dry and comfortable! I gifted these for Christmas and my step dad is hyped!

    Warm and Durable

    • Familiarity: I've put it through the wringer
    • Fit: True to size

    I use these in the winter with my waterproof boots. Help keep things warm and dry.

    Pretty warm

    • Familiarity: I've used it once or twice and have initial impressions
    • Fit: True to size

    Hiked a few times with tem. Definitely do the job. During the day, even when it was still cold, I had to put something thiner since they are actually very warm.