An air cast is a medical device that encases an injury in a cushioned casing. Air casts are designed to reduce pain and promote healing. They have an air-filled splint on the inside and a hard shell on the outside. Aircast walking boots are fairly comfortable and allow the patient to walk with a normal gait, even up and down steps. They can also be adjusted and customized to perfectly fit the patient's foot.
An advantage of air casts is that some are waterproof and you can actually take a shower in them. However, sleeping is not recommended in an air cast. You should remove the outer casing before you go to sleep and only wear the inner splint. Depending on your injury it may be permissible to take the boot off at night when you are at home. Check with your healthcare professional before removing.