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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

£28

Colour

Size

Also available in: Long Sleeve Top and Vest
Free standard delivery over £60

Reviews (673)

4.7

74% Recommended this product

Mentions
02 March 2026Ben999
Verified Purchase

Warm and Comfortable

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
Verified Purchase

Warm and comfy.

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
Verified Purchase

Warm and cosy

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
Verified Purchase

Lovely And Warm

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

Helpful?

13 February 2026Pinocchio6
Verified Purchase

Perfect

Yes, I recommend this

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

Helpful?

13 February 2026C____64
Verified Purchase

Great quality

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
Verified Purchase

Great Purchase

Yes, I recommend this

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

Helpful?

07 February 2026Fjgtiec
Verified Purchase

Average.

No, I don't recommend this

They aren’t as stretchy as I’d like and go baggy on the knees after only a couple of hours wear. I expected more for £28.

Reviewer Ratings

Comfort

Average

Helpful?

Reviewer Ratings

Comfort

Average

07 February 2026Thermal Man
Verified Purchase

My legs are toasty but too long!

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
Verified Purchase

Winter Wear

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
Verified Purchase

Warm!

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
Verified Purchase

Warm and cosy

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
Verified Purchase

First class. Very warm and cosy.

Yes, I recommend this

First class. Great quality would definitely buy again

Helpful?

31 January 2026Smart Mart
Verified Purchase

Long John Silver

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
Verified Purchase

Good quality and reasonably priced

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
Verified Purchase

Warm and comfy

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
Verified Purchase

Great quality

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
Verified Purchase

Great when the heating broke down.

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
Verified Purchase

Great quality

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

Helpful?

23 January 2026Swimmer1960
Verified Purchase

Great quality

Yes, I recommend this

Brought for husband already has some just buying more

Reviewer Ratings

Comfort

Excellent

Helpful?

Reviewer Ratings

Comfort

Excellent

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