As temperatures drop, it’s important to know how to dress a baby comfortably yet safely for sleep.

Fabric and fit are important safety considerations for your baby's sleepwear. For infants to children's size 14, Consumer Product Safety Commission regulations dictate that sleepwear must either be made of flame-resistant fabric, or fit snugly. Flame-resistant fabric must not ignite easily and must self-extinguish quickly when removed from a flame to meet government flammability requirements. Sleepwear that fits snugly does not trap the air needed for fabric to burn and reduces the chances of contact with a flame. Flame-resistant fabrics may be worn either loose or snug-fitting; they're often made of polyester, but cotton can be treated so that it's flame resistant.

When dressing baby for cooler temps, keep these ground rules in mind:

• Don't buy oversize sleepwear that's not flame-resistant (look for a label on the garment indicating flame resistance).
• Don't allow your baby to sleep in loose T-shirts, sweatshirts, or other apparel made from non-flame-resistant fabrics.
• Don't buy snug-fitting sleepwear a size or two larger so your baby has growing room. That defeats the purpose of the garment and puts your baby at risk. Snug-fitting sleepwear looks tight, but it stretches. It must have a prominent warning on the label that states: Wear snug-fitting, not flame resistant.
• For infants, we recommend a wearable blanket, or sleep sack, to replace loose blankets in your baby's crib. Sleep sacks don't fit snugly; there's plenty of kicking room. They're typically made of flame-resistant fabric, but check the garment's label to be sure.
• Don't dress your baby too warmly. Overheating may be a contributor to SIDS. Keep the temperature in your baby's room between 68 and 72ºF. Your baby shouldn't feel sweaty or hot when touched.
• Remove all soft, fluffy, or loose bedding and other items from your baby's crib, including decorative and sleeping pillows and stuffed animals. (See Safe sleep for babies: Less is more.)
• Don't use an electric blanket, heating pad, or even a warm water bottle to heat your baby's crib. An infant's skin is highly heat-sensitive and can be burned by temperatures comfortable to an adult.
• Don't let your baby share your bed. In addition to the risk that you might roll onto your baby, adult beds pose other hazards. Your baby could get trapped between the bed and a wall, headboard, bed frame, or other object. Accidental suffocation in soft bedding is another danger, or the baby could fall off the bed. If you breast-feed your baby in bed, be sure to return her to the crib afterward. (See increase in infant suffocation due to bed sharing.)
• Do not let your baby sleep in a car seat, infant carrier or other such device. These products are intended for babies that are awake and being supervised. If your baby falls asleep, move him to a firm, flat surface as soon as you can. This is particularly important for younger babies whose heads may turn sideways or fall forward and keep them from getting enough oxygen.

Learn more about baby and child product safety through the Safety Alert program with Consumer Reports and partners. And learn more about baby clothing and crib buying and safety advice in our related reports (crib Ratings are available to subscribers).