You can determine how warm a wearable blanket or velcro/zip-up swaddle will be by its tog rating, a unit of measure conveying a textile’s thermal resistance or thermal insulance. Basically, the higher the tog rating, the warmer the wearable blanket will keep your baby at night.
Wearable blankets are rated between 0.5 tog (very lightweight) to 3.5 tog (very heavyweight), with 1.0 tog and 2.5 tog being the most common weights. If baby’s room is cool, you’ll need a heavier sleep sack and/or more clothing layers, and vice versa if baby’s room is on the warmer side. The ideal room temperature for sleep is between 66-70 degrees.
Please note: This is a starting place guide ONLY and is not something you should follow to the exclusion of your own intuition. Every baby is a little different! If you have no idea where to start, try dressing your baby as described here, and also monitor your baby closely. Check the back of baby's neck. If it's warm, baby's doing great (yes, even if baby's hands are cold). If it's cool, baby is too cold. If there's perspiration, baby is too hot. We also recommend keeping a thermometer in the room so you always know the temps.
> 75°F
- 0.5 tog sleeping bag or swaddle + short sleeve shirt (or just a diaper, depending on how high the temperature rises above 75 degrees)
70-75°F
- 0.5 tog sleeping bag or swaddle + short or long sleeve shirt and pants
- 1.0 tog sleeping bag or swaddle + short sleeve shirt
67-70°F
- 1.0 tog sleeping bag or swaddle + short or long sleeve shirt with pants
- 1.5 tog sleeping bag or swaddle + long sleeve shirt or short sleeve shirt with pants
- 2.0 tog sleeping bag or swaddle + short or long sleeve shirt
- 2.5 tog sleeping bag or swaddle + short or long sleeve shirt
63-67°F
- 1.5 tog sleeping bag or swaddle + two long sleeve shirts and pants
- 2.0 tog sleeping bag or swaddle + one or two long sleeve shirts and pants
- 2.5 tog sleeping bag or swaddle + long sleeve shirt and pants
60-63°F
- 2.5 tog sleeping bag or swaddle + two long sleeve shirts and pants
- 3.5 tog sleeping bag or swaddle + long sleeve shirt, pants optional
<60°F
- 3.5 tog sleeping bag or swaddle + one or two long sleeve shirts and pants (layer up as necessary, depending on how far the temperature dips below 60 degrees)
Please note, these are simple guidelines and are not a perfect science. As with everything in parenting land, you will likely have to custom-tailor this guide to your own baby, depending on his or her preferences, metabolism, and current state.
A few other things to know…
- On How to Tell if Baby is Hot/Cold/Just Right: Everyone sleeps a little differently. While some run cold at night, others run hot. The best way to know if you’ve dressed your baby at the right temperature is to feel the back of her neck. If it is warm, she is warm. If it is sweaty, she is too hot. If it is cold, she is too cold.
- On Specific Clothing: When we say shirt, we mean shirt or bodysuit/onesie. When we say shirt and pants, we mean shirt and pants, bodysuit and pants, or one piece jammies, footed or not. It’s all good, as long as it’s cotton and breathable.
- On Cold Arms: If your little one’s arms get cold at night but baby is otherwise warm enough (you can tell by touching the back of his or her neck), opt for a lighter sleeping bag so you can dress baby in long sleeves.
Happy sleep!
Featured photo courtesy of @alyssacvillegas.