Blocking the small hole in the middle of the sensor's upper surface with an over-bandage may cause moisture to be trapped within the sensor. This could affect the ability of the adhesive to adhere to the skin. Clothing is fine to cover the sensor's hole as it does not block moisture from evaporating*.
* Over-bandage must be applied at the time of sensor application, the opening/hole in the center of the sensor must not be covered. Additional medical grade bandages/tape can be applied, but do not remove bandages/tape once applied until sensor is ready for removal.