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Heatgen™ Maximum Thermal Long Johns

Product code: T147412W

About this style

These thermal long johns combine warmth with comfort through our warming Heatgen™ fabric. Cut to a regular fit with an elasticated waist and cuffed bottoms for secure, comfortable wear. The base layer underwear keeps you warm throughout the day, while the brushback texture feels gentle on skin. Supersoft seams prevent chafing, and a keyhole fly adds everyday practicality. Perfect cold weather clothing for when temperatures drop. M&S Collection: Easy-to-wear wardrobe staples that combine classic and contemporary styles.

Maximum warmth for keeping cosy in colder climates.

M&S

Heatgen™ Maximum Thermal Long Johns

€36

Colour

Size

Also available in: Long Sleeve Top and Vest
Free standard delivery over €75

Reviews (666)

4.7

74% Recommended this product

Mentions
02 March 2026Ben999

Warm and Comfortable

Originally posted on marksandspencer.com (UK)

Yes, I recommend this

Good fit and happy with the buy. Warm and comfortable.

Reviewer Ratings

Comfort

Excellent

Helpful?

Reviewer Ratings

Comfort

Excellent

27 February 2026Feret

Warm and comfy.

Originally posted on marksandspencer.com (UK)

No, I don't recommend this

Fits husband nicely who is 5”6. He says they are warm and comfortable for working outdoors in winter.

Helpful?

24 February 2026JuleH23

Warm and cosy

Originally posted on marksandspencer.com (UK)

Yes, I recommend this

This range is so good for keeping you warm in cold weather - I wear under jeans as an extra layer and took them skiing they were a perfect base layer

Reviewer Ratings

Comfort

Excellent

Helpful?

Reviewer Ratings

Comfort

Excellent

17 February 2026suzicuq

Lovely And Warm

Originally posted on marksandspencer.com (UK)

Very warm only complaint hubby found them a little short in the leg.

Helpful?

13 February 2026Pinocchio6

Perfect

Originally posted on marksandspencer.com (UK)

Yes, I recommend this

Perfect for this weather. Bought for Family member who works outside.

Helpful?

13 February 2026C____64

Great quality

Originally posted on marksandspencer.com (UK)

Yes, I recommend this

Being buying those for my dad for years. He would not have any other brand. He loves them

Reviewer Ratings

Comfort

Excellent

Helpful?

Reviewer Ratings

Comfort

Excellent

09 February 2026Anne34

Great Purchase

Originally posted on marksandspencer.com (UK)

Yes, I recommend this

Great purchase - I bought this for my husband quality assured with Marks and spencer

Helpful?

07 February 2026Thermal Man

My legs are toasty but too long!

Originally posted on marksandspencer.com (UK)

Yes, I recommend this

V Good Quality have purchased item before - slightly short in leg for me. I’m 1880mm high but going up a size would probably mean I’d have to eat more grub and be a fatty to absorb the excess material forming the overstretched elastic waist bit.

Reviewer Ratings

Comfort

Excellent

Helpful?

Reviewer Ratings

Comfort

Excellent

06 February 2026shalari

Winter Wear

Originally posted on marksandspencer.com (UK)

Yes, I recommend this

I purchased these thermal under garments for additional warmth during this winter period. I am approaching my 80th birthday and feel the need for extra clothing during the cold days. They are comfortable to wear and do provide extra insulation against the cold temperatures. Recommended.

Helpful?

03 February 2026ChrisPacket

Warm!

Originally posted on marksandspencer.com (UK)

Bought for travelling in a northern Norway winter. Have worn them under jeans and have kept me warm for the couple of hours each day when Im out walking.

Reviewer Ratings

Comfort

Excellent

Helpful?

Reviewer Ratings

Comfort

Excellent

01 February 2026Neera

Warm and cosy

Originally posted on marksandspencer.com (UK)

Yes, I recommend this

Warm and cosy. Great to wear in the winter periods

Reviewer Ratings

Comfort

Excellent

Helpful?

Reviewer Ratings

Comfort

Excellent

01 February 2026RSP

First class. Very warm and cosy.

Originally posted on marksandspencer.com (UK)

Yes, I recommend this

First class. Great quality would definitely buy again

Helpful?

31 January 2026Smart Mart

Long John Silver

Originally posted on marksandspencer.com (UK)

Yes, I recommend this

These are brilliant! I was looking for something to complement a lighter pair of trousers that I want to wear in cooler conditions and these are it! I've even worn them with winter cords to boost the warmth factor. They're close-fitting, comfortable and a superb purchase.

Reviewer Ratings

Comfort

Excellent

Helpful?

Reviewer Ratings

Comfort

Excellent

28 January 2026Rob 1690

Good quality and reasonably priced

Originally posted on marksandspencer.com (UK)

Yes, I recommend this

Very useful and beneficial at this time of year. Good quality and reasonably priced

Reviewer Ratings

Comfort

Good

Helpful?

Reviewer Ratings

Comfort

Good

27 January 2026ClaireMiao

Warm and comfy

Originally posted on marksandspencer.com (UK)

Yes, I recommend this

Got these for my husband, he loves them, says they are very warm, no more cold legs.

Reviewer Ratings

Comfort

Excellent

Helpful?

Reviewer Ratings

Comfort

Excellent

25 January 2026K N Medora

Great quality

Originally posted on marksandspencer.com (UK)

Yes, I recommend this

Perfect for me as I work in a very cold environment

Reviewer Ratings

Comfort

Excellent

Helpful?

Reviewer Ratings

Comfort

Excellent

25 January 2026TheBestInTheWest

Great when the heating broke down.

Originally posted on marksandspencer.com (UK)

Yes, I recommend this

Hubby approves. Garment with flies is convenient. Kept him warm when our heating broke down.

Reviewer Ratings

Comfort

Excellent

Helpful?

Reviewer Ratings

Comfort

Excellent

24 January 2026Gonkie

Great quality

Originally posted on marksandspencer.com (UK)

Lovely soft thermal leggings. My dad loves to wear these for extra warmth

Helpful?

23 January 2026Swimmer1960

Great quality

Originally posted on marksandspencer.com (UK)

Yes, I recommend this

Brought for husband already has some just buying more

Reviewer Ratings

Comfort

Excellent

Helpful?

Reviewer Ratings

Comfort

Excellent

18 January 2026Ricardian

Excellent!

Originally posted on marksandspencer.com (UK)

Yes, I recommend this

Well made and very comfortable. Would definitely buy again.

Reviewer Ratings

Comfort

Excellent

Helpful?

Reviewer Ratings

Comfort

Excellent

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