Quick Answer: The recommended room temperature for infant sleep is 20-22°C (68-72°F), which is slightly warmer than the adult ideal of 15-19°C. Dress your baby in one more layer than you would wear comfortably in the same room. Check the back of their neck or chest (not hands or feet) to gauge temperature. Overheating is a greater risk than being too cool and has been associated with increased SIDS risk. Avoid heavy blankets, sleep positioners, and excessive layering. For more on what belongs in the crib, see our crib protector for sides guide.
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New parents check on their baby constantly. Is the room too cold? Too warm? Is one more layer too many? The anxiety around infant sleep temperature is real, and it is justified. Babies cannot regulate their body temperature as effectively as adults, and both overheating and excessive cold carry risks.
The good news is that the guidelines are clearer for infants than they are for adults. The safe range is narrower, the signs of a problem are identifiable, and the solutions are straightforward once you know what to watch for.
Why Infant Temperature Is Different
Adults cool themselves primarily through sweating. Newborns have immature sweat glands and cannot do this efficiently. They also have a higher surface-area-to-body-weight ratio, which means they lose heat faster in cold environments and absorb it faster in warm ones. This makes them more vulnerable to temperature extremes in both directions.
The adult recommendation of 15-19°C for sleep (see our ideal sleeping temperature guide) is too cool for most infants, particularly newborns. The slightly warmer range of 20-22°C accounts for their limited ability to self-regulate.
Overheating and SIDS Risk
Health Canada and paediatric sleep specialists consistently identify overheating as a risk factor for Sudden Infant Death Syndrome (SIDS). While the exact mechanism is not fully understood, the association is strong enough that every safe sleep guideline includes temperature management. A room at 20-22°C with appropriate clothing is the established recommendation. Heavy blankets, quilts, and excessive layering increase risk. If in doubt, dress cooler rather than warmer.
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How to Check If Your Baby Is Too Warm
Hands and feet are unreliable indicators. Babies' extremities are often cool even when their core temperature is fine. Instead:
- Touch the back of their neck. If it feels warm and dry, the temperature is right. If it feels hot or sweaty, they are overdressed or the room is too warm.
- Check their chest. Same principle. Warm and dry is correct. Hot or clammy means reduce a layer.
- Look for flushed cheeks. Redness on the face combined with restlessness can indicate overheating.
- Rapid breathing. If your baby is breathing noticeably faster than usual and the room is warm, overheating may be contributing.
Dressing for Sleep by Room Temperature
The general rule is one more layer than you would wear comfortably in the same room:
- 24°C+: A nappy and a lightweight sleeveless sleep sack. No additional clothing.
- 22-24°C: A short-sleeved bodysuit and a lightweight sleep sack (0.5-1.0 tog).
- 20-22°C: A long-sleeved bodysuit and a medium sleep sack (1.0-2.5 tog). This is the most common setup for Ontario nurseries.
- 18-20°C: A long-sleeved bodysuit, footed pyjamas, and a warmer sleep sack (2.5 tog).
- Below 18°C: Warmer pyjamas, socks, and a heavier sleep sack. Consider raising the room temperature rather than adding more layers.
Use a Room Thermometer
Your perception of room temperature is unreliable, especially at 3 a.m. when you have been under a duvet for hours. A simple digital room thermometer in the nursery removes the guesswork. Place it at crib level, not on a high shelf where warm air pools. Many baby monitors include a temperature reading, but a standalone thermometer near the crib is more accurate.
The Crib Mattress Factor
Most infant sleep temperature advice focuses on the room and clothing. The crib mattress matters too, though it gets less attention. A crib mattress that traps heat against the baby's body effectively raises the temperature they experience, even in a well-regulated room.
Crib mattresses should be firm (this is primarily a safety requirement to reduce suffocation risk) and breathable. Avoid placing memory foam or plush toppers in a crib. The firm, flat surface recommended by paediatric guidelines also happens to be the most breathable configuration.
When your child transitions from a crib to a bed (typically between ages 2 and 3), the mattress choice opens up. A ComfortCare twin at $875 with 690 individually wrapped pocket coils provides both the support a growing body needs and the airflow that helps regulate temperature through the night.
Ontario Nursery Temperatures
Winter: Forced-air heating can make nurseries warmer than the rest of the house if a heating vent is directly in the room. Consider partially closing the vent and using a humidifier (30-50% humidity). Dry heated air irritates infant airways.
Summer: Upper-floor nurseries in Brantford can exceed 24°C on hot nights. A fan directed at the wall (not directly at the crib) improves air circulation. Dress lighter and use the lowest tog sleep sack. If the room consistently exceeds 25°C, portable air conditioning for the nursery is worth considering.
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Call 519-770-0001Frequently Asked Questions
What temperature is too cold for a baby to sleep?
Below 18°C requires careful layering and monitoring. Below 16°C is too cold for most infants and the room should be warmed rather than relying on additional clothing. A cold baby may have cool skin on their torso (not just hands and feet) and may be unusually still or difficult to wake. When in doubt, keep the nursery at 20-22°C.
Can I use a blanket in my baby's crib?
Health Canada and most paediatric guidelines recommend against loose blankets in cribs for children under 12 months due to suffocation risk. Use a wearable sleep sack instead. Sleep sacks come in various tog ratings (warmth levels) to suit different room temperatures. After 12 months, a thin blanket tucked firmly at the bottom of the crib may be introduced if the child can move freely.
Is 18°C too cold for a baby's room?
18°C is within the acceptable range but at the lower end. At 18°C, dress your baby in a long-sleeved bodysuit, footed pyjamas, and a 2.5 tog sleep sack. Check the back of their neck periodically to ensure they are warm enough. If your baby seems restless or has cool skin on their torso, the room may be too cold for their comfort.
Should I use a space heater in the nursery?
If necessary, use a heater with a thermostat and automatic shutoff. Oil-filled radiators are the safest type for nurseries because they have no exposed heating elements. Never use a fan heater or leave any heater unattended in a room with an infant. Placement should be well away from the crib and any fabric. A thermostat-controlled central heating system is the safest option.
When can my child move from a crib to a bed?
Most children transition between ages 2 and 3, typically when they start climbing out of the crib. A twin mattress is the standard first bed size. At Mattress Miracle, the ComfortCare twin starts at $875 with 690 pocket coils, providing proper support for growing bodies. Visit us at 441 1/2 West Street, Brantford, or call (519) 770-0001. White glove delivery across Southern Ontario.
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