Keeping your baby warm in a crib or bassinet during winter is essential—but doing it wrong can be dangerous.

Many parents use wool blankets to keep their newborns warm, but let me tell you—it’s not safe and can increase the risk of SIDS (Sudden Infant Death Syndrome).

The American Academy of Pediatrics (AAP) advises against using blankets, pillows, or bumpers in a crib or bassinet (until 12 months).

These items can actually make things more dangerous—not more comfortable.

🩺 “AAP recommends that all babies sleep on their back, on a flat, firm, separate sleep surface like a bassinet or crib—and that the space remains free of blankets, toys, or bumpers.”

Always place your baby on their back on a flat surface to ensure safe sleep.

So, if you can’t use blankets, how do you keep a baby warm in a bassinet?

Don’t worry—there are safe and effective methods that don’t involve blankets. But before we dive into the details…

Check out this short video showing how doctors keep newborns warm immediately after birth

I hope you gave it a watch.

Now, let me share the proven tips I personally used to keep my baby warm during cold, freezing winter nights—safely and comfortably.

How To Keep Baby Warm In Crib & In Bassinet?

There are four simple ways to keep a baby warm in a bassinet or crib without a blanket. The first is maintaining the room temperature, the second is preheating the nursery, the third is keeping the nursery dry, and the last is covering the infant’s head and feet.

Doing these things allows you to keep your newborn warm in the crib and bassinet without the risk of SIDS.

Now, let’s check all these points in depth and how we can do it safely in the real world.

1.) Keep the Room at the Right Temperature

Keeping the room at the right temperature is the safest way to warm your baby at night—without using extra clothes or blankets.

🩺 Pediatricians recommend a room temperature of 70–72°F (21–22°C). Anything colder or warmer can be uncomfortable or unsafe for your newborn.

🩺 “Babies lose heat nearly four times faster than adults. Premature and low-birthweight infants have little body fat and struggle to regulate body temperature—even in a warm room.”
— Stanford Children’s Health

Here’s why this matters:

Babies are used to the warm environment of the womb. Once born, they need help adjusting to cooler surroundings. That’s why they need to be wrapped, swaddled, or kept in a warm room during their early weeks.

But be careful—too much heat is also dangerous.

Since newborns can’t move or remove clothing layers, they can overheat easily. This may cause sweating and discomfort, and worse, increase the risk of SIDS.

💡 Pro Tip: I tested different room temperatures using a baby thermometer. My baby slept best at 71°F. If it got warmer, he’d sweat. If cooler, he’d get fussy and restless.

Here’s a quick chart to help you adjust the room temperature and sleepwear:

Can I Use a Heater in My Baby’s Room?

Yes, but choose a nursery-safe heater with features like auto shut-off, tip-over protection, and adjustable temperature settings. Never aim the heater directly at your baby.

💡 I personally recommend the Vornado Nursery Heater—it keeps the room warm without drying the air or overheating.

Heater Safety Tips:

• Keep it at least 3 feet from the crib
• Choose one with auto shut-off
• Turn it off before bedtime
• Never direct heat toward the baby
• Pair with a humidifier to avoid dry air

💡 Heaters can dry out the air, leading to congestion or dry skin. Maintain 40–60% humidity for a healthy sleep space.

2.) Preheat the Baby’s Nursery

Placing your baby into a cold bassinet is like flipping a switch—they’ll wake up immediately and cry. It’s just like how hard it is for us to leave a warm bed on a winter morning.

That’s because babies rely on their body heat and surroundings to stay cozy. So before putting them in the bassinet or crib, make sure the sleep space is already warm.

Here’s how to preheat the area safely:

• Use a bassinet warmer to heat the sleep surface
• Try a crib heating pad (remove before laying baby down)

💡 My Experience: I used to wonder why my baby woke up minutes after being put down at night. Then I realized the mattress was ice-cold, even though the room felt warm. I started preheating the surface for 15 minutes using a heating pad (removed before use), and it worked wonders!

✅ Safe Practice: Use the pad to pre-warm the surface only. Remove it before placing your baby in the crib or bassinet.

💡 Pro Tip: Leave the heating pad in the bassinet for 10–20 minutes, then take it out right before bedtime.

Can I Use a Water Bottle to Warm the Bassinet?

Yes, but it’s not the most effective option. Water bottles only warm one small area. A heating pad provides more even warmth, making it the better choice for preheating.

That’s why keeping the bassinet dry is just as important as keeping it warm.

💡 The best way to do this? Change diapers frequently and use high-absorbency overnight diapers that offer up to 12 hours of dryness.

If you’re unsure whether your baby’s diaper is wet, just gently touch the front of the diaper to feel for dampness—no need to wake them.

Also, during cold weather, warm wipes using a wipes warmer. This prevents that shocking cold feeling during nighttime changes.

🩺 “Newborns make big messes, so their laundry may need frequent washing using gentle, baby-safe detergent.”
— familydoctor.org

Another smart tip: Keep extra sheets and mattresses on hand. Warm, moist fabric is a breeding ground for bacteria, and you don’t want your baby sleeping on it.

💡 Use at least three sheet sets and two mattress protectors. That way, you always have a clean set ready while the others are drying.

Practical Tips to Keep the Bassinet Dry:

• Frequent Diaper Checks – Helps avoid prolonged contact with wetness
• High-Absorbency Diapers – Choose ones designed for overnight use
• Warm Wipes – Makes diaper changes more comfortable in cold temps
• Multiple Bedding Sets – Keeps rotation clean and convenient
• Regular Cleaning – Wash sheets and bassinet parts to stop germ build-up

Keeping the bassinet clean and dry is one of the safest and simplest ways to protect your baby from chills and irritation.

For a step-by-step guide, check this: 👉 How to Clean a Bassinet & Its Mattress

4.) Cover Baby’s Head & Hands

Even if the room and bassinet are warm, your baby can still get cold—especially through exposed skin.

Newborns lose heat quickly through their head, hands, and feet because they have a higher surface-area-to-body ratio than adults. That’s why mittens and caps are so effective.

🩺 Research shows that covering a newborn’s head can reduce heat loss by 25%—even at room temperatures like 80°F.
— adc.bmj.com

👩 Dr. Mike Petric explains in this quick video why keeping a baby’s head and hands covered helps maintain body temperature:

Even if your baby wiggles around, mittens stay in place and prevent their hands from getting cold during sleep.

💡 Case Study Insight: After using soft hats in hospitals, rates of neonatal hypothermia dropped significantly.
— researchgate.net

Choosing the Right Fabric:

Wrapping a baby can be tricky—they often squirm out of blankets. But a good pair of mittens and a snug hat stay put and keep warmth in.

Other Safe Sleepwear Options:

💡 Covering your baby’s head and hands is one of the easiest ways to maintain body warmth—without relying on risky blankets.

What Should I Do on Freezing Nights?

The tips above work well for everyday cold weather, but on freezing nights, you might need a bit more warmth.

One safe and effective method? Swaddling your baby—but only if done correctly.

Swaddling provides extra warmth while keeping your baby snug and secure. Just make sure to follow safe swaddling techniques to avoid risks.

🩺 Dr. Hu from Children’s Health advises:
“Dress your baby in multiple thin layers, including socks and a hat. A good rule: your baby should wear one more layer than you.” 📌 Source

Avoid Loose Blankets in the Crib

While swaddling is okay, loose blankets or padding are not.

Blankets can easily shift near your baby’s face, blocking airflow and posing a suffocation hazard. This is especially dangerous during sleep.

📺 Want to see why this is risky?

I hope this section helped you understand how to safely keep your baby warm—even when temperatures drop below freezing.

Final Thoughts!

Keeping your baby warm at night—especially in winter—is one of the most important ways to keep them safe and comfortable.

Remember, your baby spent nine months in the womb, surrounded by consistent warmth and protection. After birth, it’s your job to recreate that comfort, safely.

You don’t need to buy everything out there. Whether it’s a bassinet heater, crib warmer, or swaddle blanket, choose what fits your baby’s needs and your lifestyle.

Here are a few more helpful guides to explore:

• How to Get a Newborn to Sleep in a Bassinet
• How to Make a Bassinet More Comfortable

💬 No one knows your baby better than you. So always trust your instincts and choose what works best for your home, climate, and baby’s sleep habits.

I hope you found this “How to Keep Newborn Warm in Crib?” guide helpful and reassuring!