Abstract: A thermometer probe sheath comprises a paper backing sheet, a first plastic sheet releasably supported on the backing sheet and a second plastic sheet overlying the first plastic sheet and sealed around its edges to the edges of the first plastic sheet except for an insertion opening at one end of the sheets. The edges of the plastic sheets at the insertion opening are coterminous with each other and with one edge of the backing sheet and notches are formed in only the coterminous edges of the backing sheet and the first plastic sheet. The coterminous edge of the second plastic sheet remains unnotched and thereby provides a stop against which a probe may be placed to expand the insertion opening. The second plastic sheet may be colored to provide a color contrast between it and the first plastic sheet to further facilitate the insertion of a probe.