When my son was a baby, he was a terrible sleeper. Even when he was in Elementary school, he was still not a perfect sleeper. I grew to just accept that until he became a teenager when I had to drag him out of bed. My son was sensitive to schedule and routine changes and was, in general, a light sleeper.
I can see this sensitivity in almost every sleep challenge he’s ever had. For example, when my son was 3 years old, he started to have a few night-wakings every night, for 3 nights in a row. I’d expect that behavior occasionally when he was 4 months old. But at 3 years-old, it was very frustrating and probably more tiring for me, since I was no longer used to it.
As you may know, there are lots of reasons that toddlers and preschoolers might wake during the night. As I thought through the possible causes of my son’s night wakings, it occurred to me just how sensitive he is to temperature. And, eureka! I knew I’d found the culprit.
Temperature and Sleep
You see, I realized that the same night he started waking, we had put thermals on underneath his fleece footed PJ’s, because it was so freezing outside and we were worried about him being cold. Instead, because of the clothing change, he was getting too hot those few nights!
Boy, was I happy to figure it out! You’d think he would say, “Mommy, I’m too hot,” but I don’t think he realized why he was waking up.
Unfortunately, he still had a bad night here and there (nightmares, insomnia, etc.), but at least he didn’t get up on most nights and not numerous times EACH night!
So, I did some homework so I could pass on the ideal temperature your baby or toddler’s room should be when he sleeps. Hopefully, my experience again will help others.
Temperature and SIDS
It is very important that you not overheat your newborn when she sleeps as it increases the risk of SIDS. It has also been shown that using a fan can decrease the risk of SIDS by 72%. Also, be sure you don’t use a second-hand mattress.
Our internal body clock controls our body temperature and when our temperature is high, like during the day, our bodies are more awake. We all have a dip in body temperature in the afternoon and we feel sleepy (Ferber calls this the “afternoon dip”). At night, when the sun goes down, our body temperature starts to drop and Melatonin (a hormone) is released in our bodies inducing sleep. Our temperature is lowest at night until around 4 a.m. our bodies start to prepare to wake up. Many parents complain about their baby’s sleep in the early morning hours. It’s the lightest sleep of the night.
What Temperature to Set Your Thermostat?
The ideal room temperature is between 65 and 70 degrees Fahrenheit (or 18.3 to 21.1 Celsius), but I recommend you use these numbers as a starting point. In my experience of over 10 years, the ideal temperature for your family will vary a little, depending on you (and your baby) and how many blankets you use. Keep in mind that your child won’t learn to keep a cover on all night until over 18-24 months.
With the air conditioning on, 72 degrees can feel cold whereas if you put your thermostat to 72 with the heater, it will probably be too hot. In the summer, at night, we keep our thermostat at 72 degrees Fahrenheit and during the winter we set it to 63 degrees Fahrenheit. Your baby or toddler’s skin should feel cool to the touch, but not frigid like their fingers are ice cubes. And, generally, your child should never be sweating.
For my youngest, we put on a onesie t-shirt, thermal pajamas, and then fleece pajamas over those this winter. For my eldest, we put just Fleece footed pajamas and to go with his sheet and comforter. In the summer, generally, pajamas and a sleep sack (or sheet and comforter) are sufficient.
I didn’t find any scientific research about this (though I’m sure it’s out there), but if our body temperature being higher in the day keeps us awake, I would venture to guess that my son was waking up partially because his body temperature was too high as much as it was because he may or may not have been uncomfortable. The moral of the story is to keep the kids warm, but not too warm, and not too cold, either, yet another parenting magic trick.