The Family Ski Packing List: What Actually Keeps Kids Warm

Three layers, no cotton, and a second pair of mittens in your backpack.

Base layer: thin, snug, wool or synthetic, its only job is moving sweat off the skin. Mid layer: fleece or a light down or synthetic jacket, its job is trapping air. Outer layer: waterproof and windproof, its job is stopping weather from destroying the two layers underneath.

The two mistakes that make children colder are counterintuitive and both feel like good parenting: putting thick socks in the ski boots, and adding another layer at the top of the run when the real problem was sweat from the run before. Both are covered below.

Deciding whether it is too cold to go out at all is a different question with a different answer, and we have written it up separately in how cold is too cold to ski with kids.

If you remember nothing else: no cotton anywhere that touches skin. Not the vest, not the long johns, not the socks, not the t-shirt under the fleece.

Cotton holds onto water. A cotton layer that has absorbed your child's sweat stays wet all day, and wet fabric pulls heat out of a body far faster than dry fabric does. So the child sweats on a warm morning run, the damp cotton sits against their chest, and by the second lift ride they are being actively cooled by their own underwear. The jacket is not the problem. The layer nobody can see is.

Wool and synthetics do the opposite. They move moisture outward through the fabric and keep insulating even when they are not completely dry. Merino wool costs more and is worth it for the layer against the skin; a cheap synthetic base layer is still enormously better than a good cotton one.

Real talk: this single swap does more for a cold child than several hundred pounds of jacket upgrade, and it is the cheapest change on this page.

Read this table as three jobs rather than three purchases. If one job is not being done, adding more of another will not fix it. That is why piling a second fleece onto a child in a wet base layer does so little.

You have been told that most of your body heat escapes through your head. It is not true, and it is worth knowing why, because the correction is more useful than the myth.

The claim was examined by Rachel Vreeman and Aaron Carroll in the BMJ in 2008, in a paper on widely believed medical myths. The head loses heat roughly in proportion to its share of body surface, on the order of a tenth, not a half. The myth appears to trace back to mid-century military cold exposure testing in which subjects were dressed in arctic survival suits with only the head left uncovered. Under those conditions the head does lose the most heat, but that is a fact about the suit, not about the head.

Here is the part that matters for your child. Head-to-body proportions are not the same in a small child as in you. Paediatric burn assessment charts, which exist precisely because clinicians need accurate body surface percentages, put an infant's head at roughly 18% of total body surface against about 9% for an adult, with the figure falling gradually through childhood. The standard clinical reference for this is the Lund and Browder chart, which adjusts by age.

So the hat advice survives, for a different and better reason. On a toddler you are covering a much larger proportion of the body than the same hat covers on you. On a teenager the head is closer to adult proportions and the hat matters correspondingly less. Neither fact is a reason to ski without a helmet.

This is the one that catches almost every family, because the instinct is exactly backwards.

Your child says their feet are cold. You reach for thicker socks, or a second pair. The feet get colder.

A ski boot is a rigid shell sized to a foot plus a thin sock. Fill the remaining space with more fabric and you compress the foot inside the shell. Compression squeezes the small vessels that deliver warm blood to the toes, and warm blood is the only thing that actually heats a foot. You have also removed the small pocket of still air that was doing the insulating. Bootfitters are close to unanimous on this, and it is the first thing most of them check.

What to do instead: one thin ski sock, pulled smooth with no wrinkles or seams bunching under the shin. Pull the sock up before the boot goes on and check there is no fold at the ankle. If the boot is still too tight in a thin sock, that is a boot problem to raise at the rental shop, not a sock problem.

The other common cause is the walk to the lift. A child who has trudged through slush in unbuckled boots starts the day with damp liners, and damp liners stay cold for hours. Buckle at the door, not at the lift.

Mittens beat gloves for younger children, and it is simple geometry. Fingers together in one chamber share their heat and present less surface area to the cold than five separately wrapped fingers. Most children under about eight are better off in mittens, and they are far easier to get onto a cold, uncooperative hand.

Whatever you choose, the cuff matters more than the insulation. A long cuff that goes over the jacket sleeve, not under it, keeps snow out on the fall that would otherwise end the morning.

The single highest-value item in your backpack is a second pair of mittens. Not a better first pair. A second pair. Wet mittens are the most common reason a child's ski day ends early, they get wet from playing in the snow rather than from weather, and no amount of money spent on the first pair prevents it. Keep the spares warm and dry in the bag and swap them at lunch whether or not anyone has complained.

On hand and toe warmers: they are useful, and they are not meant to sit against bare skin. They can stay hot enough for long enough to cause a slow burn, at a temperature low enough that the warning sensation never arrives, which is exactly why the people most affected are those least able to notice or say so. Put them in a mitten's outer pocket or between the sock and the boot liner, never directly against a child's foot or palm, and take them out at lunch to check the skin underneath.

Some honest subtraction, because a packing list that only adds is not doing its job.

Brand names on outerwear. Above a fairly low threshold, a jacket that is actually waterproof and windproof performs its one job. The premium buys durability, cut and features, not warmth. Children outgrow it in a season anyway.

Expensive kit for the child who has never skied. Borrow, buy secondhand, or use a resort's rental. Find out whether your family likes this before you equip for it.

Heated everything. Heated socks and gloves solve a problem that thin socks, dry spares and a properly fitted boot usually solve first, and for far less.

Packing for the coldest possible day. Pack for adjustment instead. Two thin mid layers you can add and remove beat one thick one you cannot, because the child's actual problem changes four times between the gondola and lunch.

And the thing that does matter and costs nothing: get them out of the top layer before the climb, not after. A child who arrives at the top already sweating has wet themselves from the inside, and the rest of the morning is spent paying for it.

Everything below earns its place by doing one of the three jobs. Quantities assume a week and a laundry room; add a day if you have neither.

Kit only works if it goes on in the right order and gets checked. This takes two minutes and prevents most cold-child incidents.

Dress from the skin outward, checking each layer lies flat. Tuck the base layer into the salopettes. Pull socks smooth and buckle boots at the door. Put mittens on over the jacket cuff, not under it. Pull the neck gaiter up before the goggles go on, so the goggle strap holds it in place. Then run one finger around the waist, wrists and neck looking for a gap where skin or a cotton t-shirt is showing.

Then check them again at the first stop, before anyone is cold. A child who has just been told to say if they get cold is not a reliable sensor, which is a point we make at greater length in the cold weather guide. You are the sensor.