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🔥 Elevate your winter game with Thermajohn – warmth you feel, comfort you flaunt!
Thermajohn Men's J-t-m-1836 thermal underwear set features ultra-soft fleece lining and lightweight, high-stretch fabric engineered for superior heat retention and moisture-wicking. Designed for a snug, true-to-size fit with a comfortable elastic waistband, this set offers breathable warmth without bulk—ideal for layering or lounging. Highly rated with over 50,000 reviews, it’s the smart, stylish choice for millennial professionals seeking reliable cold-weather comfort.



















| ASIN | B018DQI504 |
| Age Range Description | Adult |
| Apparel Fabric Stretch | High Stretch |
| Apparel Fabric Weight Class | Lightweight |
| Best Sellers Rank | #65,405 in Clothing, Shoes & Jewelry ( See Top 100 in Clothing, Shoes & Jewelry ) #16 in Men's Thermal Underwear Bottoms |
| Brand Name | Thermajohn |
| Collection Name | Winter |
| Color | Black |
| Customer Reviews | 4.6 out of 5 stars 50,407 Reviews |
| Fit Type | Snug |
| Fit to Size Sentiment | Positive |
| Garment Size Country | United States |
| Global Trade Identification Number | 00856780008398 |
| Item Weight | 12 ounces |
| Manufacturer Part Number | LYSB018DQI504-SPRTSEQIP |
| Number of Items | 1 |
| Package Quantity | 1 |
| Pattern | Solid |
| Size | X-Large |
| Sleeve Length Description | Long Sleeve |
| Sleeve Type | Long Sleeve |
| Style Number | J-T-M |
| UPC | 856780008398 |
| Unit Count | 1 Set |
D**S
Soft, comfy and warm. Fit as hoped.
Always nervous ordering brands I'm not familiar with, but took a chance and was NOT disappointed! The set of thermals came in a nice ziplock style packaging. Tried them on right away and was pleasantly surprised. Unlike the "long johns" I've had in the past, the length was from waist to ankle and the crotch area was a fit like regular sweats. Some long johns have a bunch of extra length up top when the crotch is pulled up or the crotch sags if you have the waist in position, not these. Speaking of the waistline, it is a soft elastic waistline that doesn't irritate at all, in fact you don't even notice it at all even with your outer layer on and fastened. In fact, the whole set feels velvety soft and the material has a nice stretch to it without loosing any of the insulation or feeling like its being stretched thin. The price point works much better for me than paying the expensive prices of brands like Under Armor. Bottom line is this set of thermals from Thermajohn is great and I'm ordering more to have a set for each day of the work week!
S**.
Your Hot, Thermajohns!
These are surprisingly warmer than I expected after receiving them. Seem very thin and not warm at all. WRONG! Light weight of product is very deceiving. Outfit is very warm when needed and not at all bulky like some of years ago. Very pleased with product.
B**Z
Helps while working out in the cold
I recently bought these thermal long johns for my boyfriend, who works in a cold environment, and they have been an absolute game-changer! Not only do they keep him warm and comfortable throughout his entire shift, but they also allow him to move freely without feeling restricted. The material is top-notch, providing excellent insulation without adding unnecessary bulk. One of the best things about these long johns is their versatility. He can wear them under his work uniform for added warmth or even use them as a base layer during outdoor activities. The quality is evident, and they have held up remarkably well even after multiple washes. Additionally, the fit is spot on, and he loves how they don’t ride up or bunch during the day. They are true to size and provide a snug yet comfortable fit that doesn’t hinder movement. Overall, I highly recommend these thermal long johns to anyone working in cold conditions or anyone looking for reliable and comfortable thermal wear. They have exceeded our expectations in terms of warmth, comfort, and durability. A definite five-star product!
J**H
Runs small ... Fleece is nice, but doesn't cut the wind as well as expected.
Amazon won't let me post pictures of the bottoms of these Thermajon reviews, so you only get pictures of the top. For reference, I am a 6'2" male weighing in at 190 lbs and a 33" waist. These thermal underwear are decent, I suppose is how I'd classify them. The stitching is meh, but for the price, I really wasn't expecting better. The material is decent, again, about what you'd expect for the price. The fleece lining is nice, but it doesn't cut the wind much... with a light outer shirt on over this, even a light chilly breeze was felt on my skin. For fleece-lined thermal underwear, I'd expect to not feel any wind bite for a light breeze. That said, they are pretty warm over-all. Will they stand up to prolonged sub-zero temperatures? No way. Do they do the job for a limited amount of time outside in freezing temperatures? Yeah, I think they will work. There are better options out there if you want something you can rely on to keep you alive in sub-zero temperatures. If you just want to shovel your driveway or move indoors/outdoors over the course of the day without freezing, these are a good option. They are comfortable to wear. The Mediums are very tight, like spandex / UnderArmor type shirt and pants. The large is snug fit. The XLs seem to fit pretty well... I normally wear medium or large, but these run small, so the XL I would classify as a large. Pants are another story... they run REALLY small, and don't really match the top. I would need a set of Large or XL pants and XL top to be comfortable, I think. If you like your thermal undergarmets to be tight, go with your normal size. If you want them a bit looser, go with at least one size up from what you'd normally wear. The XL pants are tight on me, though not uncomfortable. The XXL pants are comfortable, but a little too long... so I'll probably stick with the XL pants as well, but if you're shorter than I am, they are probably going to be a little long on you. For reference, the above pictures are sized MED - Large - XL - XXL in the pictures, so you can see how they are cut and fit on someone of my size.
K**.
Great buy - keeps you warm and cozy!
My husband say they are impressively warm without feeling bulky. The fabric is soft, stretchy, and comfortable enough for all‑day wear, whether you’re outside in freezing temperatures or just trying to stay cozy indoors. They wick moisture well and hold their shape after washing, which makes them a reliable winter staple. A solid choice if you want affordable thermal layers that actually perform.
S**A
Would recommend
Kept him warm out in the ocean on the platform
D**E
RELAXING FIT.
COMFORTABLE
S**H
warm ish
Bougtht for warehouse in winter. Will keep you warm but not cooking hot. does not protect against winds but under clothes helps.
A**H
Not warm… its kind of fleece
Size is good.. but is not warm enough… it’s basically just a fleece type
T**S
Buena, no excelente
El producto es calientito y cómodo, pero ya desde los primeros días es notorio que la tela se le hacen bolitas.
U**O
Very good purchase
So good I purchased another one. Keeps you really toasty even without jacket you won’t be extremely cold.
S**N
Muy bien
Muy buena! Mantiene el calor , bien a la talla
W**L
Best thermals I've got
I've got about 4 pairs of thermals. These are the best. Took them to Iceland in November. They do the job. Warm, comfortable and good fit
Trustpilot
3 weeks ago
3 days ago