A baby’s temperature naturally fluctuates throughout the day—it may rise when they are wrapped in a warm blanket or drop after a bath or on colder days. However, sometimes you might notice your baby feeling warmer than usual or showing signs of illness, such as fussiness, poor feeding, or increased sleepiness. When these signs appear, it’s possible they have a fever.
When preparing the nursery for bedtime, managing the room temperature is one of the most critical factors for your baby’s comfort and safety. Conventional wisdom suggests keeping the baby’s room between 68°F and 72°F (20°C and 22.2°C). Experts often recommend erring on the cooler side because infants, especially in the first few months, conserve body heat efficiently. Crucially, overheating has been linked to an increased risk of Sudden Infant Death Syndrome (SIDS).
However, every baby is unique. Factors like your local climate, the efficiency of your home's heating and cooling system, and the layers your baby is wearing can all influence their comfort. While you will learn your baby's specific preferences over time, it is vital to immediately recognize the signs that their sleeping environment is too hot or too cold. Read on for key signs, practical tips for safe layering, and advice on optimizing the nursery temperature.
Signs Your Baby is Too Hot While Sleeping
An overly warm sleeping environment is a significant concern for infants. If your baby is overheating, you will typically notice changes in their behavior and physical condition. In addition to being restless, crying, or having trouble settling down, an overheated baby might exhibit subtle but critical signs, including breathing faster than normal and being less responsive to touch or changes in light.
Physical Symptoms of Overheating
- Flushed red cheeks or face.
- Heat rash (small red spots, often visible on the chest).
- Skin that is hot to the touch (always check their neck, back, or chest, not their hands or feet).
- Sweating (especially visible on the head or neck).
- Damp hair or clothes.
Immediate Action for Overheating
If you observe signs of overheating, act quickly. Remove any excess clothing or blankets immediately and move the baby to a cooler environment. If symptoms do not begin to improve within 30 minutes, or if your baby is unresponsive, seek emergency medical attention.
How to Tell if Your Baby is Too Cold at Night
While overheating carries the higher risk, being too cold can also disrupt sleep and cause distress. Checking for signs of being too cold involves looking for different physical and behavioral cues.
Key Indicators of Underheating
- Fussiness, crying, or unsettled behavior.
- Shivering (though this is rare in newborns).
- The main physical sign is if their neck, stomach, or back is cool instead of warm to the touch. It is crucial to check the core body temperature in these areas, as a baby’s hands and feet naturally remain cooler than the rest of their body.
Signs of Severe Cold Exposure
In more serious cases of underheating, or hypothermia, additional symptoms may appear. You must seek emergency medical attention if your baby shows the above symptoms alongside:
- Breathing issues or slow, shallow breaths.
- Dull, pale, or grayish skin.
- Limpness or lack of muscle tone.
- Feeding issues or vomiting.
Safe Layering: Dressing Your Baby for the Room Temperature
Since blankets and loose bedding are not safe for infants due to the risk of SIDS, dressing your baby appropriately for the room temperature is the single most important action you can take to ensure comfort and safety. Until your baby is old enough to use a blanket safely (generally after 12 months of age), layering is key.
The Golden Rule of Layering
As a general rule, babies need one more layer of clothing than an adult would comfortably wear in the same environment. For instance, if you are comfortable in light pajamas, your baby likely needs light pajamas plus one thin layer, such as a swaddle or a sleep sack.
Using TOG Ratings for Sleepwear
Many modern baby sleeping bags and sacks come with a Thermal Overall Grade (TOG) rating, which indicates the garment's warmth. This rating can help guide your choices:
- TOG 0.5 (Very Light): Ideal for rooms over 75°F (24°C). Typically a light cotton onesie.
- TOG 1.0 (Light): Suitable for room temperatures between 69°F–74°F (21°C–23°C). Often used over a bodysuit.
- TOG 2.5 (Warm): Best for the recommended temperature range of 61°F–68°F (16°C–20°C). This is a lightly padded sleep sack.
- TOG 3.5 (Very Warm): Reserved for rooms below 61°F (16°C) or very cold climates.
Opt for light, breathable layers. Sleep sacks or wearable blankets should have fitted necks to prevent the baby’s head from slipping inside and allow full movement of their arms and legs. Never use weighted sleep sacks as they can prevent your baby from moving safely and freely.
Optimizing the Nursery Environment
Beyond dressing the baby, there are steps you can take to regulate the room itself:
- Ventilation: Use air conditioning or a fan to help circulate air and maintain a steady temperature. A fan can also provide soothing white noise. However, ensure the fan or AC unit does not blow directly onto your baby.
- Monitor Position: Avoid placing the crib or bassinet near direct heat sources like radiators, vents, or direct sunlight from a window.
- Thermometer Use: Keep a simple thermometer in the nursery, away from external windows, to get an accurate reading of the temperature at the baby's level.
- Safe Sleep Practices: Always follow safe infant sleep guidelines: place your baby on their back, in a crib or bassinet, with a firm mattress, and absolutely no loose bedding, pillows, bumpers, or toys. Avoid dressing your baby in anything that could cover their face or head, such as hats, during sleep.
Consult Your Pediatrician for Personalized Advice
If you have ongoing questions or concerns about your baby’s comfort, sleep patterns, or temperature regulation, their pediatrician or family doctor is your best resource. Kids’ health experts have specialized experience and can give you tailored recommendations for your baby’s specific needs, pajamas, and sleep environment based on their health and your home's unique conditions.
Frequently Asked Questions: Baby Room Temperature
A. Yes. While overheating is a major concern, an infant’s room can be too cold. If the temperature drops too low (below 60°F or 15.5°C), it can cause hypothermia, which is especially dangerous for newborns who struggle to regulate their body temperature. Always dress your baby appropriately for the room temperature.
A. No. A sleep sack (or wearable blanket) is considered safe sleepwear because it is worn over the baby's clothes and cannot cover their head or face, provided it is properly sized with a fitted neck opening. Unlike loose blankets, sleep sacks significantly reduce the risk of suffocation.
A. No. It is normal for a baby's hands and feet to feel cool because their circulation is still developing. To check their core temperature, always touch their neck, chest, or back. These areas should feel warm, but not sweaty or hot.