Guest blog by sleep expert Lise Dullaerts from @debabyslaapcoach


Many parents wonder which TOG rating is best for their little one's clothing and bedding. When can a baby become overheated and how dangerous is this? Can a baby also become hypothermic while sleeping? As a parent, you can become very uncertain at times when the weather is very hot (or cold). Let's take a closer look at these aspects.


What does the abbreviation TOG stand for?

TOG ratings/values (Thermal Overall Grade) are a measure used to indicate the warmth or thermal insulation of a fabric or clothing item. The TOG rating is often used with baby sleepwear, especially sleeping bags, bedding and blankets.

A TOG value offers parents a guideline when choosing the right nightwear for their baby or little one, so they can ensure that their little one is comfortable and does not become overheated or hypothermic while sleeping. The higher the TOG rating, the warmer the nightwear, bedding or blanket. The TOG rating scale typically ranges from 0.5 to 3.0, with 0.5 being the coolest and 3.0 being the warmest.

What should I look for when choosing a baby mattress?

There is no specific TOG rating for baby mattresses. That being said, a mattress should be breathable for good temperature regulation while sleeping. It is therefore important to prioritise safety when choosing a mattress. Here are some important factors to consider when choosing a baby mattress:

  • Breathability. Choose a mattress with good airflow and breathability. This helps reduce the risk of overheating and provides a comfortable sleeping environment. However, if the mattress cover is not breathable enough, heat will remain trapped in the mattress, resulting in an increased temperature in your baby's sleeping area and thus a higher body temperature.
  • Mattress protector for best hygiene. A rogue diaper or spit-up disaster during the night? It happens! When it does, a waterproof protector helps protect the mattress better (against stains, allergens, etc.). It is always important, however, to ask whether the mattress remains sufficiently breathable (and thus guarantees safe sleeping) when a mattress protector is placed on top.
  • Firmness. Choose a mattress that provides a firm and supportive surface for your baby. This promotes healthy spinal development.
  • Size and fit. Make sure the mattress fits snugly to the crib edge or bed edge with no gaps. This is to prevent your baby from getting stuck between mattress and edge.

As no TOG value is given to the mattress itself, it is very important to consider the TOG values of the bedding.

What is overheating?

We speak of overheating when your baby's body temperature rises above 38°C. Babies are not yet able to regulate their own temperature effectively. This is why it is important to adjust your baby's sleeping environment to prevent overheating. You can get started with these recommendations:

  • Make sure your baby's sleeping environment is neither too hot nor too cold. The ideal room temperature is generally between 16°C - 22°C. Use a thermometer to monitor the temperature in the baby's room.
  • Dress your baby appropriately: Dress your baby in light, breathable clothing appropriate for the current room temperature. Avoid overdressing your baby or using heavy blankets. (See TOG table)
  • Use appropriate bedding: Choose a firm mattress for the crib/cot or bassinet, topped with a breathable fitted sheet. Avoid using heavy blankets or quilts in the crib, as they increase the risk of overheating.
  • Position the crib away from direct sunlight or direct heat sources, such as radiators. Direct sunlight can quickly raise the temperature in the room and make it uncomfortable for the baby.
  • Monitor the baby's temperature: Check your baby's body temperature by feeling on the neck or belly. If your little one feels extremely hot or sweaty, this may indicate that they are becoming overheated. If this happens, remove a layer of clothing, remove the sheet or blanket or adjust the room temperature if possible.
  • If the room temperature is too high,​ consider using a fan or air conditioner to circulate the air and create a cooler environment. Make sure that air conditioning or fan does not blow directly on the baby.
  • Stay vigilant and observe your baby: keep an eye out for your little one's signals. Symptoms of overheating include red skin, rapid breathing, excessive sweating, restlessness or a shrill cry. If you notice any of these symptoms, take immediate action to cool your baby down.

Overheating during sleep can pose several risks and dangers to your baby. It is therefore essential to select proper clothing and bedding materials.

Can your child also become hypothermic?

Hypothermia occurs when the body loses heat faster than it can produce it, resulting in a dangerously low body temperature. Hypothermia occurs more quickly in a baby than in a child or adult because body temperature is regulated primarily through the head. A baby's head, relative to the rest of the body, is very large and takes up about 20% of the baby's entire body. It is important to keep their body temperature within a safe range to prevent hypothermia. Having said that, there's no need to fear that a breathable mattress protector will cause hypothermia. As long as a baby has suitable clothing and bedding, there is no risk of hypothermia occurring.
To prevent hypothermia, the same tips help as with overheating:

  • Provide a safe sleep environment with adequate air and heat circulation so the baby can always breathe freely and maintain body temperature.
  • Provide a room temperature between 16 and 22°C.
  • Take into account TOG values of clothing and bedding together with the temperature of the sleeping environment.
  • Keep an eye on the baby's body temperature by briefly feeling around the neck and adjust clothing layers accordingly.