Caring for your Smart Sock 2 and Avoiding Red Marks

The following article will help provide you with the best experience with your Smart Sock 2. Learn about how to select the correct size, check the fit, and more here.


Proper Care for the Fabric Sock

We recommend washing the fabric sock at least once a week. After removing the sock electronics, use cold water to hand-wash the fabric sock or machine wash the fabric sock in a garment bag on delicate cycle.

Allow the fabric sock to air dry completely before the next use. Avoid placing the sock in the dryer as the heat can possibly deform the vinyl window and cause the fabric to lose its shape faster. Learn more here.


Long-term Use of the Fabric Sock

Wear to the fabric sock will naturally occur over time. If you are planning on using the Smart Sock 2 for future children, we recommend purchasing a new set of fabric socks with every child. Find replacement socks on our website.


Sock or Sensor Discolored?

We see discolorations on sensors from time to time. It can be an issue of the ink being smeared due to the natural oils in the skin or just plain old dirt. Plastic is already a very porous material and likes to trap anything it can get. The fact that the sensor is white only magnifies this issue.  

If you notice any discoloration, simply wipe the sensor with a baby wipe or an alcohol pad. Make sure it's completely dry before charging or placing it on your little one.

What Causes Red Marks and How Do I Avoid Them?

Your baby’s well-being is our top priority and we know it’s yours, too. We are committed to the quality of our product, and as parents ourselves that use the product with our own children, we stand by it.

Newborn skin is soft, sensitive and can be quite hydrated. In the spot where the plastic window is inside the sock, since the plastic doesn't wick away moisture like fabric, that area doesn't breathe as well. If the sock is on one foot throughout the night, it is possible for newborns to develop a "water bubble" in that area. Fortunately, these are very superficial and typically reabsorb during the day. 
To prevent this, we recommend rotating the sock around every 4 hours during use until around 1 month of age to give the skin a chance to dry out more. 


A small number of our users notice red marks on their baby’s foot after use of the Owlet Smart Sock. While this is not a common occurrence, we take this seriously, which is why we want to address these red marks head on. Just like a baby shoe that is too tight or too small, it can be uncomfortable for your child and leave marks. Our research, in partnership with dermatologists and pediatricians, shows that these marks are not electrical or thermal burns.

These red marks may appear in the following areas-


Right Foot Top 



Left Foot Bottom


A: Pressure marks can be caused in a few different ways. Contributing factors include: pressure from over tightening, a sock size that is too small, your baby laying on top of the sensor by sleeping on their stomach (on the right foot), or standing on it too long (on the bottom on the left foot).

What should I do?

Check the Size

Try going up a sock size or loosening the straps on the fabric socks, they should lay flat without any ripples or puckers. Ensure the velcro is lined up so that the sensor stays straight up and down. This will help the windows line up.

Switch it Up

Rotate in between feet to prevent too much pressure being on the skin for too long.

B: These marks can be found on the top or bottom of the foot near the pinky toe where the vinyl windows in the fabric sock lay and can be caused by a few different reasons: pressure, moisture, and friction.

What should I do?


As babies grow, their feet get rounder. This can interfere with the pulse oximeter’s ability to get a good reading as it places the sensor at an angle (instead of straight up and down)- causing yellow notifications. When this occurs, the foot can also press up against the sensor, causing pressure.

The Smart Sock 2 has a weight limit of about 18-25 lbs and since every foot is different, some little ones can outgrow the sock sooner than others depending on the roundness of the foot.

Make sure that your sock placement & sock size are correct and that you are rotating the sock from one foot to the other on a nightly basis.


We recommend placing the sock on a clean, dry foot without any ointments or cream. Our sock doesn't absorb moisture as well as other socks due to the sensor components and if moisture builds up, it can irritate your little one's skin, similar to a diaper rash.

If your child tends to get sweaty or clammy feet while sleeping, we recommend ensuring a comfortable sleeping temperature, (less warm pj’s, a fan in the room, etc.) and limiting the amount of time they are wearing the Smart Sock.


If your baby seems uncomfortable due to teething, colic, or just likes to move, the constant movement can cause enough friction to create hot spots on their foot. If the skin is irritated enough, these hot spots can quickly progress into blisters. It’s the same as someone breaking in a pair of new shoes, where the shoe doesn’t match the foot. This causes repeated rubbing and irritation.

If a mark appears, the skin will need time to heal. Rest the foot with the mark on it and don’t put the sock back on until the mark has gone away. Help support the healing skin by applying a barrier cream containing petroleum jelly or equivalent several times during the day. When the mark is gone, you can put the Smart Sock 2 back on the foot, making sure that the placement & sock size is correct.

If you have any questions about whether your little one is wearing the Smart Sock 2 correctly, please take some pictures from a few different angles (top, bottom, side, etc.) and submit them to customer care so they can help check the fit. Send it to our team via the chat feature in the Owlet app or by email at


We want to help you get the most out of your Smart Sock. Using the right fabric sock size and knowing the proper placement will help provide an all-around better experience for you and your little one. If you have questions about your Smart Sock, feel free to contact our customer care team by phone, chat in via the Owlet app or send an email at