Optimal Sleep Environment for Babies and Toddlers

Room temperature

The ideal nursery temperature is between 68 and 72 degrees Fahrenheit (20 to 22 degrees Celsius). Overheating is an independent risk factor for SIDS. Babies cannot regulate their body temperature as efficiently as adults, so the room temperature and clothing choices matter more.

Signs your baby is too warm include: sweating, damp hair, flushed cheeks, heat rash, or rapid breathing. Signs of being too cold include: cool extremities (hands and feet being slightly cool is normal), mottled skin, or fussiness. Check the temperature by feeling the back of your baby's neck or chest -- these should feel warm but not hot or sweaty.

Darkness and light

Light is the strongest signal to the circadian clock. Even small amounts of light can suppress melatonin production and signal the brain that it is time to be awake. For babies over 6 to 8 weeks (when the circadian rhythm begins developing), a dark sleep environment significantly improves sleep onset and duration.

• Blackout curtains: The most effective solution for nursery darkness. Look for curtains that block 95-100% of light, particularly important for naps and early morning wake prevention.
• Night light choices: If you need light for nighttime feeds or diaper changes, use red or amber light. Blue and white light are the most disruptive to melatonin. Keep any night light dim and away from the baby's line of sight.
• Morning light exposure: Bright light within 30 minutes of wake time helps set the circadian clock and improves nighttime sleep. Open curtains immediately upon waking.
• Pre-bedtime dimming: Dim the lights in your home 30 to 60 minutes before bedtime to signal melatonin production.

White noise

White noise mimics the sound environment of the womb (blood flow, heartbeat, and muffled external noise registered at about 80 to 90 dB in utero). For babies, it provides a familiar sound backdrop that masks environmental disturbances and helps with sleep onset and duration.

• Volume: Keep white noise at or below 50 decibels (about the volume of a quiet conversation or light rain). The machine should not be louder than a running shower when standing at the crib.
• Placement: Position the machine at least 7 feet (2 meters) from the crib. Never place it on or directly next to the crib.
• Type: Continuous, steady sounds (static, rain, fan) are more effective than rhythmic or nature sounds with variations. Avoid machines with heartbeat sounds that have silent gaps.
• Duration: Run white noise continuously through the entire sleep period. Timers that shut off can cause waking when the sound changes.
• Weaning: There is no requirement to wean off white noise. Many children (and adults) use it for years. If you wish to wean, gradually reduce the volume over several weeks.

The sleep surface

The AAP recommends a firm, flat mattress that fits snugly in a crib, bassinet, or play yard that meets CPSC safety standards. The mattress should not indent when you press on it and there should be no gaps between the mattress and the sides of the sleep space (no more than two finger-widths).

• Use only the mattress that came with your crib or one specifically designed for it
• Only a fitted sheet (no mattress pad, memory foam topper, or additional layers)
• No incline (all products must be flat -- inclined sleepers have been recalled)
• Nothing else in the crib: no blankets, pillows, bumpers, or stuffed animals (until 12+ months for a lovey)

Humidity

Maintaining indoor humidity between 40 and 60% helps prevent dry nasal passages (which cause congestion and mouth breathing) and reduces the likelihood of dry skin irritation that can disrupt sleep. A cool-mist humidifier is recommended over warm-mist models to eliminate burn risk. Clean the humidifier regularly (every 1 to 3 days) to prevent mold and bacteria growth.

Sleep environment checklist