A plastic sheath dimensioned to fit securely and snugly around an arm or leg cast or bandage of a wearer includes a flexible elastic band at an open first end constructed with at least one expandable trough encircling the sheath, with a stretchable band looped over the elastic band and fitted within the trough at said first end, and with the stretchable band being rollable forwardly from the opened first end of the sheath towards an opposite sealed second end from trough to trough when it is desired to remove the sheath from being worn.
