SHIRT, a loose garment, commonly of linen, worn next the body.—Some dispute about changing the linen when a person is sick. Clean linen promotes perspiration, and it may be renewed as often as the patient pleases, whether the disorder be of the acute or the chronic kind. Except during a crisis in fevers, whilst the patient is in a sweat, a change of linen, if well dried and warmed, may be daily used.