This is a moderate temperature; ensure the sleep sack fits snugly around the neck and shoulders.
The Neck Test: Feel the back of your baby's neck or chest. If it feels hot or sweaty, remove a layer. Hands and feet are often cool to the touch and are not a good indicator of core temperature.
Never Use Hats Indoors: Babies regulate their temperature primarily through their heads. Wearing hats indoors significantly increases the risk of overheating.
Use this quick reference table to determine the correct TOG rating and clothing layers for your baby's room temperature. Remember that these are guidelines, and you should always check your baby's chest or back of the neck to ensure they are not overheating.
| Room Temperature | Recommended TOG | Clothing Layers |
|---|---|---|
| 27°C+ (80°F+)Extremely Hot | 0.2 TOG | Nappy / Diaper only or sleeveless bodysuit |
| 24°C - 27°C (75-80°F)Warm | 0.5 TOG | Short-sleeve bodysuit |
| 21°C - 23°C (69-74°F)Slightly Warm | 1.0 TOG | Short or long-sleeve bodysuit |
| 16°C - 20°C (61-68°F)Ideal (Recommended) | 2.5 TOG | Long-sleeve bodysuit + Sleepsuit |
| 14°C - 15°C (57-60°F)Cool | 3.5 TOG | Long-sleeve bodysuit + Sleepsuit |
| Under 14°C (Under 57°F)Cold | 3.5 TOG | Bodysuit + Sleepsuit + Cardigan/Socks |
A TOG (Thermal Overall Grade) rating is a measure of thermal resistance used to describe how warm a baby sleep bag or blanket is. According to guidelines from The Lullaby Trust, a lower TOG rating (0.5 to 1.0) is lighter and used in warmer weather, while a higher TOG rating (2.5 to 3.5) is thicker and designed for colder winter nights.
According to guidelines from The Lullaby Trust and the NHS, the safest and ideal room temperature for a baby to sleep in is between 16°C and 20°C (61°F to 68°F). This reduces the risk of Sudden Infant Death Syndrome (SIDS), as babies are highly sensitive to overheating.
The NHS and pediatric experts advise against checking a baby's hands or feet, as these are normally cooler than the rest of the body. Instead, feel the back of your baby's neck or their chest. If the skin feels hot or sweaty, they are too warm and you should remove a layer of clothing or lower the TOG rating of their sleep sack.
No. According to The Lullaby Trust, babies regulate their body temperature primarily through their heads. Putting a hat on a sleeping baby indoors significantly increases the risk of overheating and SIDS. Hats should only be worn outdoors.
This page outlines the authoritative source mapping used to establish the safe sleep and dressing protocols for infants. The underlying temperature matrix is built by cross-referencing published clinical data on neonatal thermoregulation with official frameworks from Western public health institutions.
Temperatures exceeding this threshold present a critical risk of severe heat stress and hyperthermia. Infants should wear only a diaper or a sleeveless cotton bodysuit, and caregivers should maximize natural airflow with a fan pointed away from the infant.
A 0.5 TOG rating paired with a short-sleeve bodysuit is the standard for this environment. Socks or footed garments should be avoided to allow for natural evaporative cooling.
A 1.0 TOG medium-weight sleep sack is recommended, paired with a short-sleeve or long-sleeve cotton bodysuit. The sleep bag must fit snugly across the neck and shoulders to prevent the infant's head from slipping inside.
This represents the target indoor sleeping environment for most European guidelines. A 1.5 to 2.5 TOG sleep bag acts as the primary thermal barrier over a long-sleeve bodysuit and footed pajamas, negating the need for any loose blankets.
A 2.5 TOG sleep bag over a long-sleeve bodysuit and footed pajamas is safe and comfortable for cooler rooms. If the infant's chest feels cool, a layer of clothing should be added under the sleep bag rather than placing a blanket over it.
For temperatures dropping below 15°C, a 3.0 to 3.5 TOG sleep bag should be paired with a long-sleeve bodysuit, thick footed pajamas, and an insulated inner layer. If active domestic heating is used to warm the house, it should be stabilized to a low target not exceeding 20°C.
Infants possess an immature thermoregulatory system and rely entirely on non-shivering thermogenesis, making them highly susceptible to rapid heat loss and metabolic cold stress in uninsulated environments.