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Heatwave Thermalwear

Heatwave® Pack Of 2 Men's Thermal Underwear Set Long Sleeve Top & Long Johns Set Durable Warm Underwear Baselayer For Outdoor Running Hiking Sportswear Workwear Advanced Insulating Yarn Comfort Fit Small Medium Large Black Grey Navy White

Regular price £16.67 GBP
Regular price Sale price £16.67 GBP
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Heatwave® Pack Of 2 Men's Thermal Underwear Set

Stay warm and comfortable no matter the weather with the Heatwave® Pack Of 2 Men's Thermal Underwear Set. This comprehensive set includes a long sleeve top and long johns, designed to provide optimal warmth and comfort during any outdoor activity. Whether you're running, hiking, or working outside, this thermal underwear set is your go-to base layer for ultimate insulation and durability.

Key Feature 1: Advanced Insulating Yarn

Description: The Heatwave® thermal underwear set is crafted from an advanced insulating yarn, providing a high-performance level of insulation. The inner layer is brushed softly to hold more warm air close to the skin, delivering a 0.45 tog rating.

Benefits: This feature ensures you stay warm in the coldest conditions, making it perfect for outdoor activities and workwear. The advanced yarn construction traps heat effectively, allowing you to stay active without compromising on comfort.

Key Feature 2: Comfort Fit & Ribbed Construction

Description: The ribbed construction of the thermal set shapes to the contours of your body, providing a snug yet flexible fit. The tops are designed to be side seam-free for added comfort, and the long johns come with an open fly for convenience.

Benefits: The ergonomic design enhances comfort during prolonged wear, reducing friction and irritation. The fitted design ensures better heat retention and allows for a full range of motion, making it ideal for sports and physical activities.

Key Feature 3: Durable Material Blend

Description: Made from a blend of 50% polyester and 50% cotton, this thermal set combines the best properties of both materials. Polyester provides durability and moisture-wicking capabilities, while cotton offers softness and breathability.

Benefits: The durable construction ensures long-lasting wear, even with frequent use. The moisture-wicking properties keep you dry and comfortable, making it suitable for various strenuous activities.


  • Small: Top (Chest Size) 34-36” : Long John (Waist Size) 29-32”
  • Medium: Top (Chest Size) 37-39” : Long John (Waist Size) 33-35”
  • Large: Top (Chest Size) 40-42” : Long John (Waist Size) 36-38”
  • X-Large: Top (Chest Size) 43-45” : Long John (Waist Size) 39-42"
  • XX-Large: Top (Chest Size) 46-48” : Long John (Waist Size) 43-45”

Note: All sizes are approximate.

Colours Or Style Options

  • White
  • Blue
  • Charcoal
  • Black
  • Navy
  • Grey

Care Guide

To maintain the quality and longevity of your Heatwave® thermal underwear set, follow these care instructions:

  • Machine washable at 40°C
  • Can be tumble dried
  • Wash dark colors separately

Why Choose This Product

Opt for the Heatwave® Pack Of 2 Men's Thermal Underwear Set for unbeatable warmth, comfort, and durability. Unlike other thermal sets, Heatwave® uses advanced insulating yarns and a unique ribbed construction to ensure maximum heat retention and a perfect fit. Our customers rave about the comfort and performance, making it a trusted choice for outdoor enthusiasts and workers alike. Experience the difference with Heatwave® and stay warm all winter long.

Additional Information

Usability: Perfect for a variety of uses, including outdoor running, hiking, sports, and workwear. Its versatile design also makes it suitable for everyday wear during colder months.

Warranty and Support: Heatwave® offers a satisfaction guarantee with a comprehensive return policy. Our customer support team is always ready to assist with any queries or concerns, ensuring you have a seamless shopping experience.


We have partnered with 20 innovative grassroot companies that we believe can help reverse climate change. We allocate a fixed margin from every sale to support fund nature-based carbon removal solutions such as reforestation and soil carbon sequestration. Fund companies such as DroneSeed, Grassroots Carbon, and Pachama.

We are committed at Sock Stack to neutralize our shipping emissions and remove carbon dioxide from the atmosphere. Learn more here.

We also work closely with Royal Mail to ensure hassle-free, on-time delivery. Generally processing times are within 1 business day*. Processing times may also be extended during holidays, launches/re-stocks, limited edition releases and promotions. We will notify you as soon as your order ships or if we foresee any issues with fulfilling your order. Read our full Shipping Policy for more information.
*Please understand that business days do not include weekends and Bank Holidays (United Kingdom).

£3.95 flat fee for all domestic within the United Kingdom (free shipping over £40), 2-4 working days.
£5.95 express fee for all domestic within the United Kingdom, 1-3 working days.

Easy returns

Not completely satisfied with your purchase? Reach out within 35 days to explore hassle-free return options. We've simplified cancelations for a full refund and additionally return requests can be made from your online account. Please review our Refund Policy for more details. Thank you for your patience and understanding as we navigate this together.


Sock Stack does not have a call centre and we're not set up to handle high volumes of phone calls.

The Sock Stack brand was built online, including our customer support. Though you may receive an automated response every once in a while, all channels are manned by human staff who are eager to help you out, quickly and efficiently.

Thank you again for visiting Sock Stack. For information on our new product launches, please follow us on Instagram & Facebook. For customer service inquiries, please send us a message on Facebook Messenger or e-mail us at For order inquiries, please include your order number for faster service.


Clearpay makes budgeting easier, allowing you to break down your payments into four installments, due every two weeks, interest free. Head over to Sock Stack and find something you love. Then, just add to bag and simply select Clearpay as your payment method at the checkout. Enjoy your new stuff right away and pay over four installments.

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Buy now and pay 30 days later with KLARNA payment portal. You get all the “closure” of a full upfront payment, but with the cash-flow benefits of spreading the cost. The total amount charged to your card is no greater than if you simply paid for the entire purchase up front.



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Sock Stack

Our Mission

Heatwave Thermalwear® envisions becoming the most celebrated, trustworthy, and sought-after brand by offering superior, distinctive, and inexpensive thermal wear products that exceed every customer's expectations. Heatwave Thermalwear's® vision is to become a leading thermal underwear baselayer brand by delivering the most refined and high-grade products to the customers that are thoughtfully developed to withstand extremely cold conditions while offering enhanced protection and unmatched comfort.

Sock Stack

Function, Fit & Style

Heatwave Thermalwear® strives to provide a diverse collection of the highest quality and affordable thermal underwear to men and women. Our thermal socks, long-sleeve base layers, long johns, hats and gloves are meticulously designed to be safe, lightweight, and breathable, providing fast-wicking and added warmth. As a customer-first brand, we are committed to fostering solid and lifelong relationships with our clients and aspire to deliver exceptional quality and value in our products.

Customer Reviews

Based on 52 reviews
Mr David Weir (Glasgow, GB)

Perfect fit, very comfy and cosy

M.B.E. (Sheffield, GB)
Great men's base layer

Recommended by a friend. Great multi pack purchase for my partner who enjoys hiking. These are lovely thermal base layers, not thin, not thick, just right. Delivery was super quick. I will use this company again


Not true to size, did not fit

Peter Cole (Southwark, GB)
Thermal underwear

Well made,good fit and value for money

Jane Sykes (Northallerton, GB)
Warm but could be a bit longer

Bought for son who’s a brickie. Says they’re warm but could do with being just a bit longer (he’s 6”5 and thin so a large would be to big around; a longer length medium size would be helpful). Likes that the long johns have a cuff at bottom of legs stops them riding up

Edwin Todd (Evesham, GB)
Excellent as ever

Excellent products, very competitive prices and high quality clothing.

James Moffat (East Kilbride, GB)
Thermal Long Johns

As described. First class


My son is over the moon with these sets 😍

Sharon Rodham (Stockton-on-Tees, GB)

Excellent value for money

Elizabeth mcmullen (Lisburn, GB)

Quick delivery