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2 Pack Heatgen™ Light Thermal Long Johns

Product code: T149483

About this style

For cold-weather comfort, these lightweight thermal underwear long johns provide warmth without bulk. Cut to a regular fit for easy movement, with soft seams for comfort. Heatsealed care labels ensure all-day comfort. Heatgen™ technology helps your body stay warm by generating and retaining heat. A practical fly front fastening completes this functional layering item. M&S Collection: Easy-to-wear wardrobe staples that combine classic and contemporary styles.

Light warmth for cooler conditions and everyday comfort.

M&S

2 Pack Heatgen™ Light Thermal Long Johns

€36

Colour

Size

Free standard delivery over €75

Reviews (595)

4.6

67% Recommended this product

Mentions
16 March 2026dwarfie

Great quality and good value.

Originally posted on marksandspencer.com (UK)

Bought these for my husband to wear under walking trousers. He is delighted with them and pleasantly surprised at the quality as they were inexpensive.

Reviewer Ratings

Comfort

Excellent

Helpful?

Reviewer Ratings

Comfort

Excellent

12 March 2026Jo JH

Comfortable

Originally posted on marksandspencer.com (UK)

Yes, I recommend this

Very comfortable, slightly big but kept me warm, prefer the men’s as they come up to my waist

Reviewer Ratings

Comfort

Excellent

Helpful?

Reviewer Ratings

Comfort

Excellent

11 March 2026Trampus94

Toasty warm

Originally posted on marksandspencer.com (UK)

Yes, I recommend this

Excellent base layers, kept me nice and warm when outside in the evening on the petanque terrain.

Helpful?

08 March 2026Happy Eva After

Fantastic quality

Originally posted on marksandspencer.com (UK)

Yes, I recommend this

My husband LOVES these! Lightweight but warm, wash really well and dry without bobbling.

Reviewer Ratings

Comfort

Excellent

Helpful?

Reviewer Ratings

Comfort

Excellent

05 March 2026Jim697

Good quality

Originally posted on marksandspencer.com (UK)

Just what I’m needed to keep me warm. Good colour and texture

Reviewer Ratings

Comfort

Good

Helpful?

Reviewer Ratings

Comfort

Good

06 February 2026lisa9003

Very warm and comfortable

Originally posted on marksandspencer.com (UK)

Yes, I recommend this

Great product ... kept us warm in -18 and not too think to wear under jeans

Reviewer Ratings

Comfort

Excellent

Helpful?

Reviewer Ratings

Comfort

Excellent

04 February 2026WorkingMum1000

good quality and price

Originally posted on marksandspencer.com (UK)

Yes, I recommend this

Bought these for my husband-add warmth with out bulk at a good price

Reviewer Ratings

Comfort

Excellent

Helpful?

Reviewer Ratings

Comfort

Excellent

31 January 2026Nickyj1

Great quality

Originally posted on marksandspencer.com (UK)

Yes, I recommend this

Perfect fit great breathable fabric nice and soft with a good stretch

Reviewer Ratings

Comfort

Excellent

Helpful?

Reviewer Ratings

Comfort

Excellent

30 January 2026KimFH

Good quality and comfortable

Originally posted on marksandspencer.com (UK)

The product is good quality and comfortable providing warmth in the Scottish winter!

Reviewer Ratings

Comfort

Excellent

Helpful?

Reviewer Ratings

Comfort

Excellent

29 January 2026standsoutside

Good quality and value

Originally posted on marksandspencer.com (UK)

Yes, I recommend this

My husband likes this thermal underwear. He prefers them to the heavier weight ones as they are a closer fit and keep him warm. I think they must be quite stretchy as he is a 40” waist and the Medium fit well. They also wash well and dry quickly.

Reviewer Ratings

Comfort

Excellent

Helpful?

Reviewer Ratings

Comfort

Excellent

27 January 2026mikkim

Excellent product

Originally posted on marksandspencer.com (UK)

My husband finds that the long john's are perfect for the cold weather . They keep him nice and warm .

Helpful?

26 January 2026AshleyP

Comfortable and warm

Originally posted on marksandspencer.com (UK)

Yes, I recommend this

Silky, soft material with enough stretch to adjust easily for movement and provide warmth for those with cold legs. Does not ride up like shorter pants, even when sat on soft furnishings. Gusset is convenient yet secure. Ideal winter wear indoors or out.

Reviewer Ratings

Comfort

Excellent

Helpful?

Reviewer Ratings

Comfort

Excellent

24 January 2026Billy555

Great quality, good price

Originally posted on marksandspencer.com (UK)

Yes, I recommend this

I have purchased these before. These performed great so I came back for more.

Helpful?

22 January 2026Ajwb

Keeping warm

Originally posted on marksandspencer.com (UK)

Yes, I recommend this

Bought these for my husband as he spends a lot of time outdoors he loves them keeps him very warm

Reviewer Ratings

Comfort

Excellent

Helpful?

Reviewer Ratings

Comfort

Excellent

20 January 2026noodles231

Light yet warm

Originally posted on marksandspencer.com (UK)

Yes, I recommend this

Good for a winter day when thicker thermals are too bulky - such as when wearing a suit

Reviewer Ratings

Comfort

Good

Helpful?

Reviewer Ratings

Comfort

Good

18 January 2026Cam32

Perfect weight for under jeans

Originally posted on marksandspencer.com (UK)

Yes, I recommend this

Nice quality fabric. Bought for my son, legs on the long side for a 5ft 2” person. Would be nice to have a choice in length.

Reviewer Ratings

Comfort

Good

Helpful?

Reviewer Ratings

Comfort

Good

17 January 2026AmandafromTonbridge

Wouldn’t be without them

Originally posted on marksandspencer.com (UK)

Yes, I recommend this

My son has worn these for sometime and during the recent cold snap my husband borrowed them from him. Needless to say he loved them and now has his own. Keeps you warm and washes well

Reviewer Ratings

Comfort

Excellent

Helpful?

Reviewer Ratings

Comfort

Excellent

16 January 2026Barry77

Very effective

Originally posted on marksandspencer.com (UK)

These thermals are very effective, convenient to wear and very comfortable

Helpful?

15 January 2026KG167

Winter warmer

Originally posted on marksandspencer.com (UK)

Yes, I recommend this

Purchased online & kept informed, collected in local store & my husband is very please with the purchase

Reviewer Ratings

Comfort

Excellent

Helpful?

Reviewer Ratings

Comfort

Excellent

15 January 2026griffgriffgriffin

Comfortable material.

Originally posted on marksandspencer.com (UK)

Good quality material. Lightweight to wear and comfortable too. Like the colour and they are a good fit just the right fit.

Reviewer Ratings

Comfort

Excellent

Helpful?

Reviewer Ratings

Comfort

Excellent

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