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Heatgen™ Maximum Thermal Fleece Top

Product code: T329224

About this style

Embrace warmth with this Heatgen™ Maximum Thermal Fleece top. The luxuriously soft fleece fabric features our innovative Heatgen™ technology for superior insulation during the coldest weather. Long sleeves and added stretch ensure a comfortable, flexible fit that moves with your body while maintaining heat retention. The sleek design makes it perfect for layering or wearing alone for maximum thermal protection. M&S Collection: Easy-to-wear wardrobe staples that combine classic and contemporary styles.

Details & care

Item details

Model Height: 5ft10"/178cm

Model is wearing size: 12, 14

Style

Added Stretch

Features

Heatgen™ technology

lightweight and supersoft, designed to keep you warm when the weather gets chilly

Composition

55% acrylic, 37% viscose and 8% elastane (exclusive of trimmings)

Care

Wash at 40°C

Do not bleach

Do not tumble dry

Do not iron

Do not dry clean

M&S

Heatgen™ Maximum Thermal Fleece Top

€29

Colour

Size

Also available in: Tops
Free standard delivery over €75

Reviews (1207)

4.8

79% Recommended this product

Mentions
04 May 2026Silly name restriction

Good product but sizing runs small.

Yes, I recommend this

Good quality however sizing not quite right. I am a standard normal 12 pretty much everywhere. This was far too small and it had to be sent back.

Reviewer Ratings

Quality

Excellent

Value for Money

Good

Helpful?

Reviewer Ratings

Quality

Excellent

Value for Money

Good

01 May 2026LJS46

Super warm

Originally posted on marksandspencer.com (UK)

Purchased this top in both brown and cream. Its unbelievably warm and very soft. A nice long body which I appreciate. I sized up two sizes and it was still quite fitted.

Reviewer Ratings

How do you feel about the size?

Small

Helpful?

Reviewer Ratings

How do you feel about the size?

Small

16 April 2026RWK

Like a lovely hug

Originally posted on marksandspencer.com (UK)

Yes, I recommend this

So soft and warm, yet light and not too thick. Has saved me on many occasions when I would have otherwise been cold. Great for wearing under another jumper or sweatshirt on really cold days. Highly recommended - I'll be buying more of these.

Reviewer Ratings

How do you feel about the size?

True to size

Helpful?

Reviewer Ratings

How do you feel about the size?

True to size

11 April 2026K10000

Look smart and warm

Originally posted on marksandspencer.com (UK)

Yes, I recommend this

Super warm. I bought them for skiing but actually wore them on rotation in the UK weather. The material is not thin.

Reviewer Ratings

How do you feel about the size?

True to size

Helpful?

Reviewer Ratings

How do you feel about the size?

True to size

05 April 2026NT0001

Wardrobe staple

Originally posted on marksandspencer.com (UK)

Yes, I recommend this

Love these tops. Really warm and soft. I practically live in these during winter!

Reviewer Ratings

How do you feel about the size?

True to size

Helpful?

Reviewer Ratings

How do you feel about the size?

True to size

03 April 2026sugarplumb

Affordable quality thermal top

Originally posted on marksandspencer.com (UK)

Yes, I recommend this

m&s thermal tops are a must have in every wardrobe the warmth and quality cannot be faulted they are a much welcomed gift as we all enjoy comfort and these are so comfortable I do wish they had more variety in colours especially we women have been waiting a long time for a navy thermal top. I highly recommend this garment .

Reviewer Ratings

How do you feel about the size?

True to size

Helpful?

Reviewer Ratings

How do you feel about the size?

True to size

03 April 2026Walfie

Beautiful

Originally posted on marksandspencer.com (UK)

Yes, I recommend this

I love this top, it’s super soft, comfortable and warm…I went on to buy two more. Well made. Washes well and good sizing

Reviewer Ratings

How do you feel about the size?

True to size

Helpful?

Reviewer Ratings

How do you feel about the size?

True to size

30 March 2026pezza999

Very warm thermals

Originally posted on marksandspencer.com (UK)

Yes, I recommend this

I wanted some new thermals for a ski trip to Norway these did not disappoint. Lovely and warm on the slopes with a soft fleece inside.

Reviewer Ratings

How do you feel about the size?

True to size

Helpful?

Reviewer Ratings

How do you feel about the size?

True to size

25 March 2026mrsplum

So Cosy!

Originally posted on marksandspencer.com (UK)

Yes, I recommend this

I love these thermal vest/tops. They are just perfect for winter wear under a jumper, very cosy.

Reviewer Ratings

How do you feel about the size?

True to size

Helpful?

Reviewer Ratings

How do you feel about the size?

True to size

24 March 202671Mum

Maximum Warmth.

Originally posted on marksandspencer.com (UK)

Yes, I recommend this

I have bought many different heatgen products over the years. Keep you warm in the winter months. A must for watching outdoor sports in the cold, wet and wind. Excellent for keeping you warm and cosy.

Reviewer Ratings

How do you feel about the size?

True to size

Helpful?

Reviewer Ratings

How do you feel about the size?

True to size

24 March 2026Tonibun

Great versatile product.

Originally posted on marksandspencer.com (UK)

Yes, I recommend this

Excellent for use under a sleeveless knit or waistcoat. Can be worn on its own. Comfortable to wear.

Reviewer Ratings

How do you feel about the size?

True to size

Helpful?

Reviewer Ratings

How do you feel about the size?

True to size

21 March 2026Karank

Love these Heatgen tops - ideal when it’s chilly!

Originally posted on marksandspencer.com (UK)

Yes, I recommend this

Lovely cosy tops ideal for colder weather- they are really warm

Reviewer Ratings

How do you feel about the size?

True to size

Helpful?

Reviewer Ratings

How do you feel about the size?

True to size

21 March 2026Nonnie11

Good quality

Originally posted on marksandspencer.com (UK)

Good quality, cosy and definitely worth purchasing for cost

Reviewer Ratings

How do you feel about the size?

True to size

Helpful?

Reviewer Ratings

How do you feel about the size?

True to size

21 March 2026Carolinepompom

Snug fit

Originally posted on marksandspencer.com (UK)

Yes, I recommend this

I have one of these from a couple of years ago & I also have the thinner ones aswell. I nearly sized down as a size12 is usually too big but luckily I didn’t as it is very snug compared with my others.

Reviewer Ratings

How do you feel about the size?

Small

Helpful?

Reviewer Ratings

How do you feel about the size?

Small

21 March 2026bondgirl21

So soft and comfortable fit

Originally posted on marksandspencer.com (UK)

Yes, I recommend this

Great item and so soft and will be a staple wear in my winter wardrobe. Thicker material than what I thought but this is an added bonus. Will be looking to buy another in a different colour for the winter. Got this item half price in the sale which is an added bonus 😀

Reviewer Ratings

How do you feel about the size?

A bit small

Helpful?

Reviewer Ratings

How do you feel about the size?

A bit small

21 March 2026bee77

New thermal tees

Originally posted on marksandspencer.com (UK)

Yes, I recommend this

Time to buy new thermal tees lovely & warm plus great quality & colours

Reviewer Ratings

How do you feel about the size?

True to size

Helpful?

Reviewer Ratings

How do you feel about the size?

True to size

20 March 2026melm1961

Warm

Originally posted on marksandspencer.com (UK)

Yes, I recommend this

Lovely and warm , but very long in the body . I’m 5’3 .

Helpful?

19 March 2026Holly1506

Great!

Originally posted on marksandspencer.com (UK)

Yes, I recommend this

Bought this to take to Iceland, it was great. Kept me very warm & toasty!

Reviewer Ratings

How do you feel about the size?

True to size

Helpful?

Reviewer Ratings

How do you feel about the size?

True to size

19 March 2026Marie154

Lovely and fluffy

Originally posted on marksandspencer.com (UK)

Yes, I recommend this

It's very soft and a nicer colour than it looked in the photos. I haven't worn it yet so can't comment on how warm it is.

Reviewer Ratings

How do you feel about the size?

True to size

Helpful?

Reviewer Ratings

How do you feel about the size?

True to size

18 March 2026hill 1

Disappointed after washing

Originally posted on marksandspencer.com (UK)

No, I don't recommend this

I bought three of the heatagen tops , yes they are warm , yes they are extremely comfortable to wear but unfortunately have become extremely bobbly! Not what I expected from M&S .. they are not something I would wear unless underneath something now as they are so bad . I bought them intending them as a top layer . Very dissatisfied.

Reviewer Ratings

How do you feel about the size?

A bit large

Helpful?

Reviewer Ratings

How do you feel about the size?

A bit large

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