It’s 9 p.m., the lights are low, and your baby is finally calm after a warm bath, dimming the lights and doing the 1000 other steps recommended in the baby books down to the t. But then the question hits: What exactly should they wear to sleep tonight? If you’ve ever second-guessed yourself about layering, room temperature, or which fabric is best, you’re not alone. New parents, especially, struggle with this part. Perhaps your baby has woken up a bit clammy to the touch and uncomfortable, or perhaps those sleepers you got at your baby shower don´t fill you with confidence.

Dressing your baby for sleep isn’t just about comfort; it’s also about creating a safe, breathable environment that supports healthy rest. While overheating can raise the risk of SIDS (Sudden Infant Death Syndrome), the good news is that it’s easy to dress your baby safely once you understand the key principles and get in a little bit of practice.

In this guide, we’ll show you exactly how to dress your baby for any season or room temperature, from how to layer smartly to understanding TOG ratings, to choosing the right fabrics for sensitive skin. With this knowledge, you'll be able to make confident choices every night.

Foundational Principles for Dressing Baby for Sleep

Creating a safe and comfortable sleep setup starts with understanding the basics. These principles apply no matter the season.

The "One Extra Layer" Rule

The general rule of thumb: dress your baby in one more layer than you would wear to be comfortable in the same room. But remember, this is just a starting point. Always watch your baby’s cues. Feel their chest or the back of their neck (not hands or feet) to assess if they’re too warm or too cold. Check how they look. Are they fussing, or do they look content?

Optimal Room Temperature

Experts recommend keeping the room temperature between 68°F and 72°F (20 °C and 22°C). If you can’t regulate the temperature with a thermostat, get a simple room thermometer to help you monitor it. To avoid drafts and loud bangs in the night, try opening a window in an adjacent room or adjust your baby’s layers as needed.  As a general rule, if the room feels comfortable to you in light layers, it’s likely comfortable for your baby too; just add one extra layer for them.

Transitioning from Swaddling

Swaddling can help newborns sleep more soundly by calming their startle reflex. But once your baby shows signs of rolling over (typically around 2–4 months), it’s time to transition out. A sleep sack is the safest next step.

Note: Avoid weighted swaddles. The AAP does not recommend them due to safety concerns.

The Role of Sleep Sacks and Wearable Blankets

Sleep sacks are a game-changer. They keep babies warm without the suffocation risk of loose blankets. Bonus, they allow full movement, help prevent sudden temperature drops during the night, and often become part of a soothing sleep routine.

Essential Safe Sleep Practices (Beyond Clothing)

• Always place the baby on their back to sleep,
  

• Use a firm, flat sleep surface (crib or bassinet with a fitted sheet),
  

• Keep the sleep space free of pillows, blankets, stuffed animals, and bumper pads. They look cute, but are not recommended.
  

• This one is controversial, but as a general rule of thumb, most experts advise avoiding bed-sharing for infants under one year.
  
  

Understanding TOG Ratings: A Guide to Thermal Comfort

So how do you know which sleep sack or onesie to use on a cool night versus a warm one? That’s where TOG ratings come in.

What is TOG?

TOG stands for Thermal Overall Grade. It’s a unit of measurement that tells you how warm a fabric is. The higher the TOG, the more insulation the garment provides. You´ll see this in everything from blankets to outerwear.

How to Interpret and Apply TOG Ratings

Here’s a quick guide:

• 0.2–0.5 TOG: Lightweight, best for warm temps (75°F / 24°C and up),
  

• 0.5–1.0 TOG: Mild temps (70–74°F / 21–23°C),
  

• 1.0 TOG: Cool but not cold (68–70°F / 20–21°C),
  

• 2.5 TOG: Cold nights (61–68°F / 16–20°C),
  

• 3.5 TOG: Very cold (below 61°F / 16°C).
  
  

Detailed Guide: How to Dress a Baby for Sleep by Temperature

Let’s break it down by room temperature so you can make quick, confident decisions at bedtime.

Baby Sleepwear Guide by Room Temperature and TOG Rating

Warm Weather and High Temperatures (75°F / 24°C and Above)

Keep it minimal. A diaper or sleeveless bodysuit with a lightweight organic muslin sleep sack is enough. Skip hats and check for signs of overheating like sweating, flushed cheeks, or a hot neck.

Mild Temperatures (70–74°F / 21–23°C)

Opt for a short- or long-sleeve bodysuit with a breathable sleep sack around 0.5 TOG. Organic cotton or lightweight jersey fabrics work well here.

Cooler Temperatures (68–69°F / 20°C)

Layer up with a long-sleeve onesie and footed pajamas, paired with a 1.0 TOG organic cotton sleep sack.

Cold Weather and Low Temperatures (Below 61°F / 16°C)

Go for multiple layers: socks, mittens, footed pajamas, a onesie, and a 2.5–3.5 TOG sleep sack. Natural fibers like wool and quilted organic cotton add extra warmth without synthetic chemicals.

Choosing the Right Fabrics for Baby Sleepwear

Your baby’s skin is delicate, and what they wear overnight can either support or irritate their system.

Choose breathable, non-toxic materials like:

• Organic cotton, gentle, breathable, and safe for sensitive skin,
  

• Linen, great for warm climates and naturally antimicrobial,
  

• Wool, especially merino wool, helps regulate body temperature in both hot and cold conditions.
  
  

Avoid synthetic fabrics like polyester fleece, which can trap heat and often contain formaldehyde or flame retardants. Even bamboo can be problematic due to chemical processing. At Treehouse, we use only 100% certified natural, non-toxic organic cotton fabric for our baby sleepwear—so you can rest easy.

Explore our collection here.

Addressing Common Parental Concerns and Practical Tips

Every baby is different, and no guide can replace your parental instincts. That said, here are a few helpful things to keep in mind.

Recognizing Signs of Discomfort

If your baby is too warm, you may notice damp hair, flushed skin or redness, or fussiness. Too cold? Cool hands, paleness or blotchiness, fussing, and curling up tightly can be signs.

Adjusting for Individual Baby Needs

Some babies sleep warm, others run cool. Trust your baby’s cues and don’t be afraid to tweak layers slightly from one night to the next to find the right mix for you.

Practicality and Ease of Care

Life with a baby is messy. Look for sleepwear that’s machine washable, holds its shape, and is easy to get on and off during middle-of-the-night diaper changes.

Durability and Sustainability

We believe baby clothes should last beyond the first growth spurt. That’s why we design our sleepwear to be washable, breathable, and responsibly made, with future generations in mind.

Conclusion: What It All Comes Down To

Safe, comfortable sleepwear can make all the difference in your baby’s rest and your peace of mind. Remember the basics:

• Dress your baby in one extra layer,
  

• Use TOG-rated sleep sacks instead of loose blankets,
  

• Stick with natural, breathable, and certified fabrics,
  

• Follow safe sleep guidelines recommended by pediatricians.
  
  

But above all, trust yourself. You know your baby best, and your instinct is worth its weight in gold. With the right tools, you’ll build a cozy, secure bedtime routine that helps everyone sleep better.

Sweet dreams from all of us at Treehouse.

Want help picking the perfect sleepwear for your baby’s needs? Reach out to us here, or explore our curated organic cotton and linen sleep collection.