The ornamental design for a medicalinfraredthermometer, as shown and described.
FIG. 1 is a first perspective view of a medical infrared thermometer showing my design;
FIG. 2 is a second perspective view thereof;
FIG. 3 is a front view thereof;
FIG. 4 is a back view thereof;
FIG. 5 is a left side view thereof;
FIG. 6 is a right side view thereof;
FIG. 7 is a top plan view thereof; and,
FIG. 8 is a bottom plan view thereof.
The dashed or broken lines shown in the drawings depict portions of the medical infrared thermometer in which the design is embodied that form no part of the claimed design.