zzZipMe Sacks replace loose blankets for a safer sleep. At SwaddleDesigns, we offer a full range of Sleeping Sacks in a selection of fabrics with different weights to keep your baby comfortable at any time of the year. Our sacks also feature our innovative 2-way zipper which makes diaper changes easy. SwaddleDesigns was the first baby product company to introduce the 2-way zipper on a sleeping sack for babies in 2008.

The Chart below will help guide you to select the right fabric depending on the ambient temperature of the room in your environment. For example, if your winters are cold you would want to select one of our Cozy zzZipMe Sacks. In the summertime heat, a muslin zzZipMe Sack wearable blanket is a good solution to keep baby comfy at sleeptime.

When your baby is fully past the swaddle phase (Stage 1 - 0-3 months) and has completely transitioned or weaned from the swaddle (Stage 2 – 3-6 months), then baby is ready for Stage 3 in safe sleepwear (most often between 6-18 months of age).

So again, when baby has fully transitioned from swaddling and is no longer awakened by the startle (Moro) reflex, this means baby is ready to sleep well in a loose-fitting wearable blanket or sleeping sack. Our zzZipMe sacks come in a variety of styles and materials so you can always find the right option for your baby.

How to select the best sleeping sack for baby? Its best to use our chart above. Start by considering whether baby will be using the zzZipMe Sack in the Spring, Summer, Autumn or Winter, and consider the Sleeping Sack a wearable blanket. Just like you change the bedding on your adult bed according to the season, you will want to select the right fabric for baby’s zzZipMe Sack.

If you live in a warm climate all year long, you would most likely just need Cotton Muslin, and perhaps some Cotton Flannel or Cotton Knit for when the temps dip a bit.

In very warm weather you may just need a diaper under the muslin sack, and if it gets cooler you can add a bodysuit or long sleeved cotton pajamas underneath. Touch and feel baby's neck, back or tummy to ensure they are warm and dry.

But if you live in a climate with seasons, and it gets cold at night, consider one of the Cozy styles or Baby Velvet.

Layer underneath with long sleeve cotton pajamas, and if needed you can add an additional bodysuit layer underneath the cotton pajamas in even cooler environments.

The TOG number mentioned on the chart represents a level of thermal resistance. The higher the number the warmer the sack. The TOG numbers are used as a general guide when dressing your baby for sleep. Every baby is a bit different, so it’s best to touch and feel your baby to ensure they are not too hot or too cold but comfortably warm, so they can sleep well.

A good rule of thumb, as recommended by the AAP, is to dress baby in no more than one layer more than you would be comfortable in the same environment.

What is a sleep sack? A sleep sack is a sleeping bag with a neck hole and arm holes, and is also known as a sleeveless bunting, or wearable blanket. It replaces loose blankets for safer sleep, and cannot be kicked off, so baby stays safely covered for warmth all night long. It is sleeveless to allow for airflow to avoid overheating baby. Overheating is a risk factor for SIDS, hence the sleeveless design to avoid overheating. SwaddleDesigns zzZipMe Sacks are sleeping sacks with a dual pull (2-way) zipper instead of a one-way inverted zipper. Our 2-way zipper makes is easier to use than an inverted zipper, because the caregiver does not have to try to connect the zipper under the baby’s chin.

When should you stop using sleep sacks? You should stop using a sleep sack with a swaddle wrap when baby shows signs of rolling over. The AAP recommends that babies who show signs of starting to roll over should no longer have their arms fully restrained in a swaddle, so sacks with wraps with Velcro® or other wrap fasteners should no longer be used, typically past 8-12 weeks. Sleeping sacks without a swaddle wrap may be used into toddlerhood. So sleeveless sleeping sacks or wearable blankets or zzZipMe Sacks may be used past 18 months of age. If baby is not sleeping well in a loose fitting sleeveless sleep sack then try using SwaddleDesigns Transitional Swaddle Sack which has uniquely shaped little sleeves that partially suppress the startle reflex when the mitten cuffs on the ends of each sleeve are closed, and baby, if they were to roll over, has enough mobility use their arms to push up to reposition their head because their arms are not fully restrained.

What’s the point of sleep sacks? Sleeping sacks provide a safe cover for babies who can roll over and no longer experience awakenings caused by the startle reflex. Sleeping sacks replace loose blankets which should not be used because loose blankets or quilts can become suffocation or entanglement hazards.

Are weighted blankets or weighted sleep sacks ok to use? The AAP recommends against using weighted sleep sacks or weighted blankets with babies. Weighted sleeping sacks and weighted blankets have not been determined to be safe for sleep by the AAP task force on SIDS, so the AAP does not recommend using them.

How do I know what size of sleep sack is right for my baby? Your baby's age and length are going to play the biggest roles in determining what size of sleep sack you'll want to purchase to give them the best night's sleep that's as safe as possible. Check out the sizing chart below for more information!