Portwest thermal jersey B123

Portwest Men's Polycotton Thermal Jersey B123

Reference PWB123

In stock: Ships within 48 hours

€16.90 TTC

Quantity	Discount	You Save
2	8%	Up to €2.70
3	12%	Up to €6.08
5	15%	Up to €12.67
10	18%	Up to €30.41
25	21%	Up to €88.70
50	24%	Up to €202.75
100	27%	Up to €456.19

Satisfied or refunded

Secure payment

SUMMARY

Built for cold-weather work and activity, the Portwest B123 thermal jersey provides a breathable base layer that retains warmth and wicks moisture away. Its polycotton knit stays soft over long wear, on site as much as outdoors. Stated protection down to -20 °C, in a men’s fit available from XS to 5XL. An ideal base under a fleece and a parka.

TECHNICAL DESCRIPTION

Polycotton Thermal Jersey Men Portwest B123

Material Breathable polycotton

Layer Base layer

Comfort Down to −20 °C*

Sizes XS to 5XL

Portwest Reference B123

Thermal base-layer jersey for work and outdoor activity in extreme cold

The Portwest B123 thermal jersey is a base layer made for men who work or move outdoors as temperatures drop. Its polycotton knit (50/50, 200 gsm) stays soft against the skin while wicking moisture away to keep the body dry. Designed as the foundation of a layering system, it delivers warmth and comfort through long days. The maker states protection down to −20 °C, varying with activity and the layers worn. It comes from XS to 5XL, in a men’s fit.

Grand-Froid expert's view

The smart base-layer habit: put it on against the skin in the morning, forget about it, and let it wick sweat all day. For the lower body, pair it with the Portwest B121 thermal long johns: same logic, a coherent set from collar to ankle. Under a fleece and a parka, you handle extreme cold without overheating.

Men’s thermal jersey Portwest B123 - Base layer cold -20°C

DUO OFFER — JERSEY + LONG JOHNS −10 %

A complete base layer from top to bottom: add this jersey and the Portwest B121 thermal long johns to your basket to automatically get −10 % on both items.

The discount is applied directly in your basket.

What is it designed for?

A base layer for men exposed to the cold, at work as much as outdoors.

Cold-weather work: chilled warehouses, construction, outdoor logistics where you stay exposed for hours
Winter activity: sites, handling, travel when the temperature drops
Under workwear: a discreet layer that keeps you warm without restricting movement
Layering system: an ideal base under a fleece and a work jacket
Complete it with the Portwest B121 thermal long johns for a full base-layer set, from top to bottom

Technical specifications

Type: long-sleeve jersey, thermal base layer
Material: polycotton knit, 50 % polyester / 50 % cotton, 200 gsm, soft and breathable
Protection temperature: stated down to −20 °C depending on activity and layers
Fit: men’s fit, close to the body
Properties: insulating, retains warmth, wicks moisture
Manufacturer reference: Portwest B123

Composition

50 % polyester — strength, shape retention and fast drying
50 % cotton — softness and comfort against the skin
Weight: 200 gsm

Size guide

Men’s fit, close to the body, true to size. If in doubt between two sizes, choose the larger for layering comfort.

Size	FR size (indicative)
XS	42/44
S	46
M	48
L	50
XL	52
2XL	54
3XL	56
4XL	58
5XL	60

Indicative equivalences — tolerance ± 1 size depending on body shape.

Care & Durability

Washing: machine wash at low temperature, inside out
Drying: air-dry preferably; gentle tumble if needed
Ironing: cool iron, avoid overheating the synthetic fibres
Durability: the polycotton knit keeps its shape and comfort wash after wash
Good to know: always follow the sewn-in care label

Return or exchange — 30 days

You have 30 days after receipt to request a return or exchange for this item.

Why choose the Portwest B123 jersey?

Because it plays the key base-layer role: handling thermoregulation and moisture wicking closest to the skin. It is the foundation on which all comfort in extreme cold rests.

The three-layer system:

1st layer — base (this jersey’s role): next to the skin. Captures heat and wicks moisture outward.
2nd layer — mid: fleece, thermal sweatshirt. Insulates and traps warm air.
3rd layer — outer: parka, work jacket. Shields from wind, rain and snow.

For a complete base layer, pair this jersey with the Portwest B121 thermal long johns: coordinated top and bottom, the same dry-warmth logic.

* Indicative temperature, varying with activity, body shape and the layering system worn.