Sleeping Bags for Kids in Cold Weather: Ratings That Hold

For a child sleeping in temperatures near freezing, buy a bag rated 15 to 20F, sized so the child’s head is within about 6 inches of the hood, and put it on a sleeping pad with an R-value of 3 or higher. Treat the number on a kids’ bag as a limit, not a comfort rating: a 20F bag is comfortable for most children to about 30F, and a child sleeps colder than an adult in the same bag because they have less body mass to heat the space inside it. The four bags below carry real 15 to 20F ratings in kids’ lengths; most “kids’ sleeping bags” on Amazon are rated 40 to 50F and belong in a backyard in July.

What the number on a kids’ bag means

Adult bags from major brands are tested to the ISO 23537 standard, which produces a comfort rating and a lower limit. Kids’ bags are almost never tested that way; the “15” or “20” on the label is the maker’s own estimate and usually corresponds to the limit, the temperature at which a warm sleeper is not yet cold. Parents who track overnight lows report the same pattern across brands: a 20F kids’ bag keeps a child comfortable to the high 20s or low 30s, and a 15F bag to about 25F. One family on a long-running forum thread ran REI’s 25F Kindercone on their 4 and 7-year-olds down to 25F lows with no complaints, and adult 5F bags down to 18F.

So subtract 10 to 15 degrees from the label to get a comfort temperature, and buy for the coldest night you expect, not the average. A fall weekend forecast at 38F will hit 30F in a valley campsite.

Size the bag to the child

Dead air is the enemy. A 4-year-old in a 5 ft 6 in bag has nearly 2 feet of empty space below their feet that their body has to heat all night, which is the main reason “just buy the adult bag, they’ll grow into it” ends in a cold kid at 2 a.m.

Kids’ bags are sold by “fits to” height: 4 ft, 4 ft 8 in, 5 ft, 5 ft 6 in. Pick the one closest above the child’s height. If the bag is more than 6 inches too long, do one of three things: cinch the bottom with a strap or a hair tie, fold the foot end under the pad, or stuff a fleece jacket into the foot. The Big Agnes Duster takes a different approach with exterior hooks and loops that shorten the bag’s length and width, so it can be sized down for a 4-year-old and let out over several seasons.

A bag with a hood and a draft collar is worth more than any extra ounce of fill. Heat leaves through the opening around the shoulders, and a toddler will not keep a separate hat on.

The pad does half the work

Every sleeping bag is compressed flat under the sleeper, so the insulation below the body is the pad, not the bag. For nights near freezing, use a pad with an R-value of 3 or higher; a closed-cell foam pad (R-value about 2) under an inflatable gets there cheaply and protects the inflatable from the child’s toys and zippers. A kids’ air mattress with no insulation value is the most common cause of a cold child in a warm bag.

The Big Agnes Wolverine makes this explicit: it has no insulation on the bottom at all and a sleeve that holds a 20 inch wide pad in place, so the child cannot roll off the pad in the night. Whether that is a feature depends on whether you already own a 20 inch pad. If the child sleeps on a cot, the same rule applies; cot fabric has no insulation and cold air moves under it, so the pad goes on top of the cot.

Four bags rated for cold

Kelty Mistral Kids 20

A 20F synthetic mummy that fits a child up to 5 ft, weighs about 2.6 lb, and usually sells under $60. CloudLoft synthetic fill, dual zippers, a full-length draft tube and a hood. It is the straightforward choice for ages 5 to 11 on car-camping trips in the 25 to 40F range. Check price on Amazon

Big Agnes Duster 15

Rated 15F with 30 oz of synthetic fill, fits up to 5 ft 6 in, and the one bag here that grows with the child: hook-and-loop tabs on the outside shorten both length and width, so a 4-year-old is not heating 2 feet of empty bag. List price is about $120. Big Agnes does not say whether the 15 is a comfort or limit figure; treat it as a limit. Check price on Amazon

Big Agnes Wolverine 20

A 20F synthetic bag that fits up to 4 ft 8 in, for ages roughly 4 to 9. The bottom is an uninsulated sleeve that holds a 20 inch pad, which keeps a thrashing child on the pad all night and saves weight; it also means the bag is only as warm as the pad under it. Pair it with an R-value 3 or higher pad. List price about $130. Check price on Amazon

Morrison Outdoors Big Mo 20

A toddler bag for 18 to 36 months: 20F to 60F range, down fill, about 12 oz, with sleeves, no hood and no drawstrings, so it is a wearable bag the child cannot slide down inside. It is the only product in this list made for a child who still sleeps in a travel crib. Price is around $80 to $100. Check price on Amazon

How to dress a child for a 25F night

Dry base layer (wool or synthetic, never the cotton they hiked in), dry socks, fleece pants and top, and a hat for a child over a year old. Put the next day’s clothes in the bag’s foot to warm them and fill dead space. A fleece liner adds roughly 5 to 10 degrees for a few dollars. A hot water bottle in a sock, placed at the feet for a child old enough to push it away, is the oldest trick there is; do not use one with a baby or toddler.

Zip the bag fully and pull the hood drawcord so only the face shows. Children sleep hot for the first hour and cold after midnight, which is when the bag is tested.

Babies and toddlers are a different product

A standard sleeping bag is not safe for a child who cannot climb out of it, and loose bedding is not safe in a crib. For a baby, the answer is a wearable sleep bag rated for the temperature, worn over layers, in a travel crib on the tent floor; see camping with a baby in cold weather for the layering and the safe-sleep rules. For where that crib goes in the tent, see camping with a baby: where do they sleep. Older children who want a cot under the bag should read the best camping cot for kids first, since a cot changes the pad requirement.