Thank you for contacting Product Support. No it is only made to hold one 12X13 insert at one time. You should order two inserts so that when you are using one the other can be getting cold in your freezer and will be ready when the one in your wrap gets warm.
1 Being overweight: Excess body mass can decrease blood circulation, causing fluid to build up in the feet, legs, and ankles.  Standing or sitting for long periods: When the muscles are inactive, they canât pump body fluids back up toward the heart. The retention of water and blood can cause swelling in the legs.
The technical name for this condition is âchronic venous insufficiencyâ (CVI) but not all swollen legs are caused by CVI. Get your legs checked by a doctor just in case you have a heart or kidney problem, which can also cause water retention in legs feet and ankles. Swollen legs are also common in pregnancy and are caused by the pressure of the baby on the veins in the pelvis.