A thermometer for measuring a surface temperature having in its lower portion a spiral bimetallic strip mounted centrally on the lower end of a spindle whose upper end carries an indicating pointer. The spindle is journaled in an elongated tubular stem carrying at its upper end a dial face bearing angularly spaced indicia with which the pointer cooperates for indicating temperature. The lower end of the stem has fixed thereto a cup-shaped shield, downwardly open, surrounding the bimetallic strip, and including means restraining angular movement of the outer end of the bimetallic strip, but permitting limited axial movement of the strip and spindle relative to the stem and shield.