8 Best Thermal Shirts for Men

Two fleece-lined shirts at the lowest price of any pack here, which makes this the cheapest way to find out whether you like this kind of layer. What we didn’t expect is how warm they are for something so thin: the fleece traps heat, the close cut keeps it there, and you don’t arrive at work looking like you dressed for a summit.

The inside is soft enough to wear against bare skin, which isn’t a given at this end of the market, and the outside is smooth and faintly shiny — the reason they slide under a work shirt instead of dragging on it. The fit is genuinely close, as a compression shirt should be, and it doesn’t loosen up over the course of a day.

Treat them as underwear and they’re superb value: under a uniform, under gym kit, under anything you don’t want to bulk up. They aren’t a shirt for wearing on their own — the sheen gives them away — but as the layer nobody sees, they do what the expensive ones do.

The mock neck is the whole reason to choose this one. A collar that comes up to the base of the throat closes the gap a crew-neck base layer leaves when you zip a jacket over it, and the body is cut long enough to stay tucked when you bend, reach or sit down in it.

Under Armour calls it fitted, and that’s honest — close through the torso and arms without the squeeze of a true compression top. We like it for a layer that’s on all day under a shirt: you get the warmth without feeling bandaged, and the fabric is smooth enough that a cotton shirt slides over it rather than clinging. If you wanted compression to hold muscle, this isn’t it.

The seams are the thing to watch. They can fray at the shoulder after a hard season, so check the stitching when the shirt arrives rather than discovering it in February. What you’re paying for is the collar, the length and a fit that disappears under everything else in the wardrobe.

Force is Carhartt’s base-layer line, and the shape tells you what it’s for: slim through the body, long enough to stay tucked, and cut to sit under a work shirt without a wrinkle showing through the back.

Midweight is the right word for it. The waffle holds warmth while you’re moving without cooking you the moment you step inside, which makes this the layer for a cold commute, a shift on your feet, or a climb that keeps you working. Worn on its own it reads as underwear; under something else it disappears, which is the job.

The fit is the selling point — snug enough to trap heat, long in the body, slim enough that a shirt over it still hangs properly. If your cold is mostly standing still, though, a sideline or a deer stand or a breakdown on the shoulder, the Access heavyweight below is the better buy; this one rewards movement.

Weight is the argument. This is one of the two true heavyweights in this guide: a thick, closely knit thermal that holds heat like a sweatshirt, with sleeves long enough to keep your wrists warm. If you feel the cold and you aren’t moving much — a walk, a sideline, a cold workshop — this does the most warming for the least money of anything here.

It runs large, so go a size down unless you want it loose, and wash it cold, because a warm wash can shrink it. Those quirks aside it’s the simplest shirt in the group: a crew neck, long sleeves and a straight cut that layers under a flannel or a hoodie without the bulk of a sweater.

We keep coming back to it in the coldest weeks, when a fleece-lined layer feels too thin for the walk to the car. It isn’t the shirt for a hike; it’s the shirt for everything around the hike.

Not every thermal shirt is underwear. This is a waffle-knit henley with a button placket and a collar that stands up on its own, and it’s built to be seen — with jeans, over a T-shirt, under a jacket on a cool evening.

The cut helps: athletic through the chest without clinging, and the waffle has enough texture to look like a choice rather than a layer. It’s a thin knit, though, and you can feel the difference the moment you put it beside a fleece-lined base layer.

Which is the point. This is a shirt for the cool half of the year, not for February, and worn over a tee it handles a chilly morning and a heated office in the same day. It looks good enough that nobody asks why you’re wearing long johns to dinner. Buy it as a shirt, not as a layer.

Rib-knit cuffs, a henley placket and a knit thick enough to stand away from the body — everything about this shirt says it’s meant to be the outer layer, not the one underneath.

Worn over a T-shirt on a cold morning it does the work of a light sweater without the bulk: the knit is dense rather than lofty, so it sits close at the shoulders and falls straight through the body. The cuffs are the detail we appreciated most — ribbed, snug, and they keep the sleeve where you put it when you push it up to wash your hands.

The cut is roomy, and a size down still leaves space for a T-shirt underneath, which is how this shirt works best. Sleeve length is the measurement to check against the size chart if your arms run long.

At the top of the price range it’s the most expensive way to buy a thermal here, and the construction is what you’re paying for: a placket that sits flat, seams that don’t pucker, and a shape that survives being worn as a shirt rather than a layer. It’s the one in this group that feels like a garment first and a thermal second.

A five-pack in the same mould as our top pick — fleece lining, compression cut, long sleeves — for a little less money.

The difference is in the hand-feel. The knit is smooth and stretchy, with enough give through the shoulders that reaching overhead doesn’t turn into a fight with the shirt, and it’s soft enough to forget you’re wearing it under a jersey or a hoodie.

Sizing runs small, so go up a size if you’re between — a compression fit leaves no room for optimism. In a pack of identical dark shirts, that’s the detail that decides whether they get worn.

Where it earns its place is price and feel together: five shirts, a smooth finish and enough stretch for the gym, at less than the pack we recommend first. If your size is straightforward and you like a slicker fabric against your skin, it’s a good buy.