Baby Sleep and Temperature

The son this website was inspired by is a MUCH better sleeper than when he was a baby, but he will probably never be a perfect sleeper and I have grown to just accept that (maybe I will have to drag him out of bed as a teenager — we’ll see). My son is sensitive to schedule and routine changes and is, in general, a light sleeper. Last week he started to have a few night-wakings every night for 3 nights, which nowadays is unusual. When he was 4 months old it was common, expected and highly frustrating. At 3, it is no less frustrating and probably more tiring since I’m no longer used to it.

It was my own article last week that helped me figure out what had changed. I wrote my article about baby temperament and sensitivity, and it reminded me just how sensitive he is/was to temperature. And, it was 2-3 nights prior that we thought it was very cold at night and we put thermals on underneath his fleece footed PJ’s. Now that he’s older, he keeps the sheet and blanket on him a lot better, so 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 has a bad night here and there (nightmares, insomnia, etc. — which I hope to write about in the future), but at least he doesn’t get up most nights and not numerous times EACH night like last week!

So, I did some homework so I could pass on the ideal temperature your baby or toddler’s room should be when he sleeps, so hopefully my experience again will help others.

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%.

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.

I found a few sites that say the ideal room temperature is between 65 and 70 degrees Fahrenheit (or 18.3 to 21.1 Celsius), but none of the sites seemed like THE authority on that, so I’d use that as a starting point, but I’m going to venture to guess that 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 past 18-24 months. My youngest, we put on a onesie t-shirt, thermal pajamas and then fleece pajamas over those this winter. For my eldest, we are now putting on just Fleece footed pajamas and he has a sheet and comforter on. And, we’re keeping our thermostat at 68 degrees at night.

I didn’t find any scientific research about this, 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.

At what temperature do you keep your thermostat?


  1. Donna says

    We too keep the thermostat at 68 degrees. My husband was concerned about the proper temperature when our daughter was a baby and asked her doctor. He said not below 68 degrees overnight. Now that she is in a big girl bed we have adjusted her winter pajamas to include fleece and/or socks on the coldest of nights and regular cotton on the warmer nights.

  2. says

    Our thermostat is at about 68, but where she sleeps is freezing. Do they wake up if they’re too cold, too? I’m afraid to bundle her up too much because I don’t want her to get too warm. But when she wakes up in the middle of the night (presumably to eat, but maybe cause of the temperature) her little hands and lower arms are cold, and sometimes her feet are too. Should I put more clothes on her?

  3. says

    @Donna Thank you for sharing your experience.

    @Lainie Yes, I would think they would wake up if they are too cold just the same as if they were too hot. If you’re comfortable, it’s harder to sleep. You might try one more layer on her, but I’m not sure what she’s wearing now. They say to put one more layer on them than you have on.

  4. Joyce says

    My son’s room is colder than ours, even though the thermostat says 70 it feels much colder than that. We started using a space heater in his room at night, and he is now sleeping better. In fact at almost 11 months, he’s finally sleeping through the night! Now I wonder if he’s been waking up because it was too cold?! He’s little hands are now warm. :)

  5. Karin says

    I bought a remote thermometer to monitor the temperature…the thermometer stays in her room and digital readout piece is in our room. It gives me piece of mind because I was worrying about the same thing. Her room is chillier than the rest of the house, but luckily we have a space heater in there, which we keep at about about 67-68 degrees…that seems to be best for her. I feel like the few nights it got hotter than that, she didn’t sleep as well, so I’m happy to hear the same from the rest of you. We dress her in PJs (weight depending upon temp) and then use a fleece sleep sack, which is great.

  6. Lainie says

    That’s all helpful to read. I got a space heater, but I’m too paranoid to let it run while she’s asleep. So I run it before, then turn it off. I think it has helped. The spot where she sleeps was about 60 degrees. Brrrr.

  7. Rebecca says

    I was just wondering, at what age to you stop adding that extra layer to keep them warm and have them wear just the same clothes as us?

    My daughter is 15months old and her room is warmer than ours, (in summer it’s a horrible 28 degrees celcius at night in there) which makes it hard for me to be sure she’s not too hot without actually being in the room myself. I don’t want to give her that extra layer, as I’ve read many times, in case it’s too hot… I also read that too much heat induces bad dreams and I REALLY don’t want to do that lol.

  8. says

    @Rebecca I can attest to when my son is too warm, he seems to have more nightmares, too. We kept an extra layer on our son until he was in a regular bed and when he started keeping (most of) the covers on most of the night. Our younger son is still in extra layers because he doesn’t keep a blanket on, yet, and he’ll be 2 in February. Hope this helps!

  9. Lori says

    We have a thermometer in our 8-month-old’s room and try to keep the temp at 69 or 70. However, the temperature changes drastically at night, and we’re afraid to go in and check because he is such a light sleeper. Just the click of the door opening will wake him sometimes. Thanks for all of the experiences.

    Karin, I love the idea of a remote thermometer! Where did you get it?