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Terramar Thermawool ClimaSense® 4.0 Base Layer Pants - Merino Wool Blend, UPF 50+ (For Men)

Item #128NP
$39.99 Save 38% Compare at $65.00
XL (Waist 40-42) Reset selected size
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About Terramar Thermawool ClimaSense® 4.0 Base Layer Pants - Merino Wool Blend, UPF 50+ (For Men)

Closeouts. Who turned up the heat? Must be those heavyweight Terramar's ClimaSense® 4.0 base layer pants! Featuring a soft-and-cozy blend of fleece and merino wool fibers, these moisture-wicking bottoms keep you warm and protect you from the sun, keep your body's climate under control and quash odor-causing bacteria.


Specs about Terramar Thermawool ClimaSense® 4.0 Base Layer Pants - Merino Wool Blend, UPF 50+ (For Men)

  • Base layer weight: Heavyweight
  • UPF Rating: 50+
  • Inseam: 31" (based on size Medium)
  • Fabric: 70% micropolyester, 30% merino wool
  • Lining: 100% polyester
  • Care: Machine wash, tumble dry
  • Weight: 9.1 oz.
  • Made in China
  • Visit our Layering Guide


Terramar Mens Size Chart

Chest 34 - 36 38 - 40 42 - 44 46 - 48 50 - 52
Sleeve 31 - 32 32 - 33 33 - 34 34 - 35 35 - 36
Waist 28 - 30 32 - 34 36 - 38 40 - 42 44 - 46

Note: Measurements are in inches. Tall measures 2" longer overalll and 1" at sleeve.


Do you own this product? Write a review and help others with their buying decisions!

4.600000 5 Overall Rating: 4.6 Based on 40 reviews

Most Helpful 5-Star Review

Terramar ClimaSense® 4.0 Base Layer Bottoms - UPF 50+ (For Men)
Verified Buyer Reviewed by Rick from Northern MI on Wednesday, January 4, 2017
Fit - as ordered. I ordered large and the fit is great. I am 5'11" and 165
Really warm. I am a ski instructor and work outside when not skiing and have been very comfortable
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  • nice and warm!
    Verified Buyer Reviewed by karlos from idaho on Thursday, February 15, 2018
    bought these to replace an old pair of fleece pants i've worn in conjunction with long johns under skow bibs for years. the terramar bottoms were warm enough to replace the (2) layers. wore them under snow bibs in 25 degrees last weekend and they were great!
  • Ride low and slide down
    Reviewed by Brian Myers from Minnesota via South Carolina on Wednesday, February 7, 2018
    Warm, but the bottoms are NOT even functional. They ride low and work their way down from there with any activity, ending up at the crotch. I would have returned them immediately if I tried them on right away. Tops are OK
  • Comfy and Warm!
    Verified Buyer Reviewed by DangerRanger from St. Louis on Wednesday, January 24, 2018
    Used these under a pair of general sweatpants while it was -5 - 15oF in the Midwest this winter. I could walk for over an hour with this base layer and a base top combined. Great buy for a great price!
  • Great pair of base layers
    Verified Buyer Reviewed by undertakr11 from Miami, Florida on Sunday, January 7, 2018
    I purchased 4 of these for my husband. This was our first ski trip and we were not sure what to buy. These were awesome. He loved them and they kept them warm. We went to Colorado.
  • Didn’t know pants had a neck hole.
    Verified Buyer Reviewed by Xmas let down from Bellmore, NY on Tuesday, December 26, 2017
    Wife ordered the pants in darker grey for Christmas and o opened to my surprise, and hers, the light grey baselayer shirt. Was going to just purchase the pants on line as well in size small, but of course, only X & XL. Moral of the story : open package right away before you gift it bc may not be what you or other person wanted.

Question & Answer

Questions about this product? Get answers from community and staff experts.

  • “Do these have a fly?”
    Asked by Christopher Fenger from Maine on 1/24/2018 8:36:50 AM
    • My husband said it had a fly but he never used it.
      Answered on 1/24/2018 9:10:46 AM by undertakr11 from Miami, Florida
    • Yes, these have a fly.
      Answered on 1/24/2018 10:05:30 AM by Product Specialist from Sierra Trading Post
  • “I'm 6ft, 185lbs. 36-38, or 40-42 for waist size? Will they shrink?”
    Asked by JoeCar from Mi on 3/5/2017 9:14:33 PM
    • I have a size M (32-34). If anything, these are on the roomier side for fit, as I wear 34 or 36 waist in jeans. They're a comfortable roomy as opposed to actually fitting too large.

      As for shrinkage, I've not had that problem, however I wash these (and all of my synthetics and wools) in cold water and hang to dry.

      I really like these. I hate when long underwear shrinks. It's bad enough trying to move around wearing layers.

      BTW: if you happen to own a pair of Ice Breakers long underwear, it might help you to know that a size L Ice Breaker fits about the same as a size M Terramar brand.
      Answered on 3/5/2017 11:14:58 PM by Walking the dog in Minneapolis from Minneapolis
    • If you're wearing 36" jeans now, for example, get the LG [36--38] and they'll be fine especially if your inseam is 32". Follow wash instructions, Low/Cool settings for wash/dry, and the shrinkage will be minimal. Love these base layers to tears for the North West winter we've had. Where you're from, I guess they'd be essential!
      Answered on 3/6/2017 11:40:03 AM by Barusu from near Portland, Oregon
    • These should not shrink. According to information listed under the product Overview/Specs tab:
      Fabric: 70% micro polyester, 30% merino wool
      Lining: 100% polyester
      Answered on 3/8/2017 4:19:09 PM by Product Specialist from Sierra Trading Post
    • I own two sets of the Terramar top and bottoms. Both have been washed per instructions several times without noticeable shrinkage. The warmest base layer products I have found. I am a ski instructor in N. Michigan and spend a lot of time outside on the slopes and these are great.
      Answered on 3/11/2017 5:18:52 AM by Rick from MI
    • I'm about exactly the same height as you but 30 lbs heavier. The XL fit me perfect. You want long underwear to fit snug and not too baggy to layer other clothes over them. I think the L should fit you.
      They are 70% polyester and 30% Merino wool. I wash them in cold water with biodegradable non-detergent laundry soap. I would never put them in the dryer. They dry super fast anyway. As long as you don't over-dry them, they should never shrink.

      Hope this helps you and you are off to a great adventure in these awesome long underwear bottoms!
      Answered on 3/11/2017 10:31:00 PM by Salmon KIng Dave from Michigan
  • “I'm 35" waist. 5' ,9" and 175lb. I will wear these for stalking deer and elk in mountains. Should I get a large or medium?”
    Asked by Bob T from WA on 1/12/2017 10:43:56 AM
    • Bob, I am a 34 waist, 5'11" and 165 and the large is just a wee bit large but I like the extra room. I would think the large would work for you also. Rick
      Answered on 1/12/2017 11:10:36 AM by Rick from MI
    • I'm 34" waist, 5' 6" and 164lb. Mine are size medium and fit comfortably, definitely not tight. I don't think an extra inch or two would make a difference. The length is definitely more than sufficient for me. You might wish the mediums were an inch longer, but you'd also wish the large weren't so loose at the waist. I'd say go with the medium, assuming the obvious; you'll be wearing warm socks that come well above your ankles.

      These really are a nice product. The thickness is about medium weight. The product description says they're heavyweight, which I expect is correct in terms of temperature control. I've not tested them in the wilderness, so I can't speak to how they compare to other heavyweight base layers.

      Have fun!!!
      Answered on 1/12/2017 2:04:51 PM by Walking the dog in Minneapolis from Minnesota
    • HI. I would buy a different pair. I loved these at first and my husband did as well. The combo of wool makes for a nice, thin and very warm layer. However, the elastic waistband began to lose it's elasticity just after 6 washings, therefor it wouldn't matter what size you get because after 6 washings, any size will fit you! I wanted to return these but decided not to spend the postage to do so.
      Answered on 1/12/2017 5:54:42 PM by Helen from massachusetts
  • “What is the wool % of the blend?”
    Asked by TLB from Utah on 12/4/2016 10:41:36 AM
    • 30% wool / 70% polyester
      Answered on 12/4/2016 12:23:00 PM by Helen from Athol
    • This information can be found under the Specs tab. Fabric: 70% micro polyester, 30% merino wool
      Answered on 12/7/2016 8:05:25 AM by Product Specialist from Sierra Trading Post

About Terramar

The individuals behind Terramar socks and clothing understand that spending time outdoors is a great way to have fun and get exercise. To help outdoor enthusiasts stay comfortable in a wider range of conditions, this brand has spent decades perfecting the science of layering. Crafted using advanced fabrics, Terramar base layers, shirts, socks and underwear provide excellent thermal regulation and moisture-managing performance. Whether you’re carving up the slopes, snowshoeing, hiking or climbing, a breathable, quick-drying Terramar base layer is the perfect solution to keep you in the comfort zone when the mercury drops.