How to dress your baby for sleep

Temperature and safety

When your baby is sleeping, it’s essential that they do so in a space where they can move and breathe freely. To reduce the risk of suffocation, avoid placing pillows, blankets, or soft toys in the crib, and ensure there’s no chance of your baby getting trapped or overheating.

Keeping your baby at a comfortable temperature is also crucial, as it serves as a protective factor against sudden infant death syndrome (SIDS). Making sure the sleep environment is safe and well-regulated will help promote a secure and restful night’s sleep.

Check your baby and evaluate

The best way to know if your baby is at a comfortable temperature is to observe and feel them after they’ve been lying down for a while, ideally just before you go to bed.

To check, feel your baby’s torso—specifically between the shoulder blades or on the chest. If your baby is overdressed, you may notice they feel warm and sweaty on the neck and chest after a short time. You can also look for signs like flushed skin or damp hair.

If you’re concerned that your baby might be too cold, feel their torso for an accurate temperature check. However, most healthy babies will wake up and show discomfort if they’re feeling too cold.

It’s best to avoid checking your baby’s face, hands, and feet, as these areas can often feel cooler and provide misleading information about their overall comfort.

What temperature should the room be when the baby sleeps?

A common recommendation for room temperature is around 20-21°C (68-70°F), but some babies may sleep better in a cooler room with more layers of clothing. The key is to ensure that your baby is not too warm and that you adjust their clothing based on the room’s temperature.

Avoid placing your baby near heat sources, such as hot pipes or radiators, and don’t use hot water bottles, as these can pose a risk of overheating or burns. Additionally, be mindful of temperature changes throughout the night. For example, if you increase the heating before bed, make sure to check that the room doesn’t become too warm as the night progresses.

By staying aware of the room’s temperature and how your baby is dressed, you can help create a safe and comfortable sleep environment.

Pajamas, onesie, and/or sleep sack

How much clothing your baby needs while sleeping depends on both the room temperature and whether your baby tends to run warm or cold—it can vary quite a bit! It’s important to experiment and assess what works best for your little one.

When selecting clothing and layers for your baby at night, opt for soft, breathable materials that will keep them comfortable. Avoid clothing with uncomfortable buttons or strings that could cause discomfort or pose a risk of getting caught. This way, you can ensure your baby sleeps soundly and safely throughout the night.

Pajamas or onesie

A soft, thin cotton pajama with long sleeves and legs is often a good starting point if the room temperature is around 20-21°C (68-70°F). Choose a pajama that fits just right—not too big or too tight—to ensure your baby’s comfort.

For easier diaper changes or nighttime changes, a onesie with a zipper is usually convenient. It doesn’t need to go over the head and can be quickly put on or taken off.

If you need to add more layers, consider using a sleep sack over the pajamas. A sleep sack is a safe alternative to a blanket, which can pose a suffocation risk.

Sleep sack

A sleep sack can be used either as a replacement for pajamas or as an additional layer over pajamas, taking the place of a blanket. You can also use a sleep sack over a bodysuit, allowing the baby’s legs to be covered only by the sleep sack.

Sleep sacks come in various thicknesses depending on how warm you need them to be. When purchasing one, check if it’s labeled as lined or unlined, and sometimes the recommended room temperature for the sleep sack is also indicated.

For a more precise way to evaluate the warmth of a sleep sack, look for its TOG rating (Thermal Overall Grade), which describes how warm it is. This can help you choose the right sleep sack based on the room temperature and your baby’s needs.

What does TOG rating mean?

The TOG rating is a measure of insulation in textiles, typically ranging from 2 to 15 or higher. A higher TOG value means better insulation and, therefore, more warmth.

Low TOG value (around 0.5-1.0 TOG): These are suitable for warm and summery nights. They offer less insulation and are ideal for warm climates or warm indoor environments.

Medium TOG value (around 1.0 to 2.5 TOG): These are suitable for cooler indoor temperatures during spring and autumn, providing balanced insulation and warmth.

High TOG value (3 TOG or higher): These are appropriate for colder indoor environments, such as in winter, depending on how your home is heated. They offer high insulation and warmth.

As always, it’s important to assess the actual temperature in your home and observe how warm your baby feels with different layers. Adjusting layers based on these factors will help ensure your baby stays comfortable and safe during sleep.

Note – Always follow the indoor temperature and not just the season.

Should I use a hat and socks?

It’s generally not recommended to have a hat on your baby indoors, as it’s easier for them to regulate their temperature without one. Allowing their head to be uncovered helps prevent overheating and allows natural temperature regulation.

Socks, either loose or as part of a onesie, can be used if you choose. Some believe that keeping the baby’s feet warm with socks can help regulate their overall body temperature, as cold feet can signal the body to raise its thermostat. However, make sure the socks are not too tight and that your baby remains comfortable.

Consider how many layers you are wearing

When figuring out what your baby needs to stay comfortably warm, you can start by considering how many layers you're wearing. While everyone varies a bit, this can serve as a helpful starting point:

• If you’re wearing a t-shirt (or nothing) and a thin blanket: A thin, full-length cotton pajama might be suitable for your baby.

• If you’re wearing a sweater or full pajamas and a medium-thick blanket: A cotton pajama combined with a medium-thick sleep sack could be just right.

• If you’re wearing a t-shirt, a thick blanket, and a wool blanket: Your baby might need a cotton pajama and a thicker sleep sack, or a wool/silk pajama with a medium-thick sleep sack.

This method allows you to gauge your baby's needs based on your own comfort level, but remember to observe and adjust as necessary to ensure your baby remains comfortable throughout the night.

Merino wool pajamas

Soft merino wool pajamas can provide excellent insulation and help your baby maintain a steady temperature in cooler weather, like during the fall and winter. Merino wool is also great at wicking away moisture and stays warm even if it gets damp.

To avoid a scratchy pajama, look for higher-quality brands. Finer wool usually has longer fibers, making it less likely to itch. Many wool pajamas for babies also include silk to make them extra soft.

While wool pajamas might cost a bit more than cotton ones, you can often find affordable, good-quality wool garments secondhand, especially in sizes between 50-92, since babies outgrow them quickly.

Another advantage of wool is that it doesn’t need to be washed as frequently as cotton. You can often wipe it clean and air it out between uses, so having just two pajamas to alternate between might be enough.