AAP recommends breathable cotton to prevent toddler overheating

Key facts

The American Academy of Pediatrics identifies overheating during sleep as a recognized SIDS risk factor, and its current guidance on HealthyChildren.org names fabric choice as one of the most controllable variables parents have. The AAP recommends dressing toddlers for sleep in soft, breathable cotton and specifically cautions against fleece and synthetic fabrics that restrict airflow. Sleep medicine specialists aligned with AAP guidance set the safe bedroom temperature range for babies and toddlers at 65 to 70 degrees Fahrenheit (18 to 21 degrees Celsius).

• Overheating is a recognized SIDS risk factor, per AAP guidance published on HealthyChildren.org
• Recommended bedroom temperature for toddler sleep: 65 to 70 degrees Fahrenheit (18 to 21 degrees Celsius)
• The AAP advises breathable cotton for toddler sleepwear and cautions against fleece and other synthetics that trap body heat

What it means for parents

For parents deciding whether to add socks at bedtime, the AAP's layering rule is the practical guide: dress your child in one more layer than you would need to feel comfortable in the same room. In a nursery running below 65 degrees Fahrenheit, a thin pair of cotton socks fills that extra layer without adding bulk or trapping heat. In a room already within the recommended range and with a child wearing footed pajamas, socks are unnecessary, and a synthetic or thick pair could push skin temperature above what the body needs for restful sleep.

Fabric matters beyond comfort. A 2022 peer-reviewed review by McCabe and colleagues, published in Frontiers in Psychiatry and indexed at PubMed Central, examined the relationship between thermal comfort and children's sleep. The authors found that clothing and bedding form a thermal microclimate around the body, and that even modest temperature changes beyond the thermoneutral zone can delay sleep onset, reduce slow-wave sleep, and increase nighttime waking. Natural fibers such as cotton regulate this microclimate more reliably than sealed synthetic fabrics, which trap moisture and raise skin temperature as the night progresses. The review also identified REM sleep, the stage linked to memory consolidation and emotional processing, as particularly vulnerable to thermal discomfort.

Background and context

Young children's peripheral circulation, including blood flow to the feet and hands, is still maturing, which means toddler feet can feel cool to the touch even when core body temperature is normal. This gap sometimes leads parents to add layers to a child who is already warm enough. The AAP addresses this directly: check the back or chest, not the hands or feet, for signs of overheating such as sweating, a hot chest, or flushed skin. The extremities are a poor proxy for a toddler's actual core temperature.

A separate line of research connects the sensory environment at bedtime to how readily toddlers settle. A 2020 observational study by Appleyard and colleagues at the University of Otago, published in the American Journal of Occupational Therapy, found that bedtime challenges in typically developing toddlers were significantly associated with individual differences in tactile and sensory processing. The authors concluded that attending to touch and texture inputs from clothing at bedtime is a practical area where caregivers can reduce friction for sensitive children. For toddlers who consistently resist settling, the feel of a sock seam pressed against the toe can be the kind of low-level tactile input that prolongs wakefulness.

Takeaway

The guidance from the AAP and from peer-reviewed sleep research points in the same direction: keep the sleep room between 65 and 70 degrees Fahrenheit, choose breathable cotton over synthetic fabrics, and layer conservatively. When socks are the right call, thin and cotton is the right sock. For toddlers who show signs of tactile sensitivity, a seamless toe construction removes one contact point that can interrupt settling. SUNBVE's seamless-toe combed cotton crew socks carry both qualities in a 10-pack sized for toddlers and older children.