When you need to take your hands out of a mitt to do something, and when your outer glove has room to spare. Those are the two cases. A merino liner under a shell adds warmth and gives you a working layer for the moments a bare hand would freeze — but stuffing one into an already-snug glove makes your hands colder. Our gloves and mittens range covers both parts of the system.
The circulation problem comes first
Hands stay warm because blood carries heat to them. Anything that compresses the hand restricts that flow, and a restricted hand gets cold regardless of how much insulation surrounds it. This is the same principle that makes thick socks counterproductive in a fitted ski boot.
A liner added to a glove that already fits closely reduces the air space and squeezes the fingers. The result is usually colder hands, not warmer ones. Liners work when the outer glove was sized with them in mind, or when the outer is a roomy mitt or shell.
What a liner is actually for
The main argument is not warmth. It is that a liner lets you take the outer layer off briefly without exposing bare skin. Adjusting a binding, working a camera, handling a rope, digging in a pack, checking a phone — all of these are awkward in mitts and painful with bare hands below about −10°C.
A thin merino liner keeps a usable amount of dexterity while preventing the immediate heat loss and the risk of skin sticking to cold metal. For anyone whose day involves repeatedly stopping to do something fiddly outdoors, this is the whole justification.
Why merino rather than a synthetic liner
Hands sweat, particularly inside a waterproof shell glove where there is nowhere for moisture to go. A damp synthetic liner becomes clammy and cold as soon as you stop moving. Merino absorbs moisture vapour into the fibre and continues to insulate while damp, which suits the enclosed environment inside a glove.
Merino liners also do not develop odour over a season the way synthetic ones do, and they are pleasanter against skin than most thin synthetics. The trade-off is durability: a fine merino liner will wear through at the fingertips faster than a nylon one, which is why blended liners are worth seeking out.
When to skip the liner entirely
- Your gloves already fit closely. Adding a layer will compress your hands. Buy a warmer glove instead.
- You never take your hands out. If the outer stays on all day, the liner is doing little a warmer outer would not do better.
- Very wet conditions. A saturated liner inside a shell is worse than no liner, and it dries slowly.
- High-output activity. Hands generate warmth during hard work; a liner alone is often enough and the outer stays in a pocket.
- Your hands are cold because your core is cold. The body restricts blood flow to extremities to protect core temperature, so a warmer base layer often fixes cold hands better than any glove.
Fitting a liner and outer together
Buy the pair together, or bring your liners when buying the outer. A shell glove or mitt fitted over a liner should still leave a small amount of air at the fingertips — that trapped air is doing much of the insulating, and a glove packed solid with fabric has none.
Liners should be close-fitting without compressing, with as little seam bulk at the fingertips as possible. Touchscreen-compatible pads are genuinely useful, since the alternative is removing the liner as well and defeating the point.
Weights and what they are good for
Liners come in a narrower range than most merino garments, and the differences matter more than the numbers suggest. An ultralight liner is essentially a second skin — maximum dexterity, minimal warmth, and the right choice if the outer glove is doing all the insulating.
A midweight liner is warm enough to wear alone on a mild day, which makes it the more versatile purchase for commuting, dog walking and driving. It is also thick enough to change how an outer glove fits, so size accordingly.
Blended liners with nylon at the fingertips last considerably longer than pure merino ones. The fingertips are where every liner fails first, because that is where the fabric works against whatever you are handling.
Where liners fit in a winter system
For most people the sequence is: a warm, well-fitted outer that leaves room; a thin merino liner inside it; and a warm core so that the blood reaching your hands is warm to begin with. Mitts are warmer than gloves in serious cold, because fingers sharing air stay warmer than fingers separated, and a liner restores enough dexterity to make mitts practical.
Our Canadian winter layering guide covers the core layers, and choosing a merino toque covers the other extremity that decides comfort. A hat and liners together cost little and address where cold is felt first.
Related merino guides
Sources
- CCOHS: working in the cold
- CCOHS: cold environments and health effects
- REI: how to dress in cold weather
Image: Merino Mart catalogue. Browse gloves and mittens.